Big Changes Coming For Severe Weather Outlooks

Whether it be on the air or on this blog, you may notice that I regularly refer to severe weather threat zones in anticipation of severe weather events that may impact West Central Ohio. The National Weather Service’s Storm Prediction Center, or, SPC is responsible for these outlooks that meteorologists around the country communicate to the public. These changes will take place next Wednesday, October 22nd and will add two more categories to the severe weather scale.

Up until now severe weather threats were communicated with 4 categories. The SEE TEXT category being the lowest which basically meant a very marginal risk for severe weather. The SEE TEXT was then followed by SLIGHT RISK, MODERATE RISK and finally HIGH RISK.

Personally, I found the SEE TEXT category confusing. I knew it meant a very marginal threat for severe weather, so instead of saying SEE TEXT on air I chose to describe it as “VERY SLIGHT” which you may have noticed whenever I use my graphics to show severe weather threat areas.

But things are changing! Here is a look at the new way the SPC will be outlining future severe weather risks after October 22nd. This is taken from their website which can be found here. After looking over the changes my thoughts on the change can be found at the bottom.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Experimental SPC Day 1, 2, 3 Convective Outlook Change Page

Overview of the Experimental SPC Day 1-3 Outlook Change

Updated August 8, 2014: Service Change Notice 14-42 has been issued. The changes will be implemented effective Wednesday, October 22, 2014 at 1500 UTC.

Product Description Document (PDD): https://products.weather.gov/PDD/SPC_Day_1to3_Cat_Conv_Outlook.pdf.

The public comment period ended on June 17, 2014.

Q: How are the outlooks changing for Day 1, Day 2 and Day 3?

A: The SPC will revise Day 1 through Day 3 categorical severe weather outlooks to better communicate risk and describe the likelihood of severe weather. Format changes will also improve the use of SPC severe weather forecasts for customers who incorporate SPC outlooks into GIS systems.

The SPC is expanding the risk categories from four to five and clarifying the risk previously labeled as “See Text.” That descriptor will be replaced by a categorical line and the term “Marginal” to denote areas with a 5 percent probability of severe weather. The upper end of the “Slight Risk” category will be renamed “Enhanced” (short for “Enhanced Slight”) to denote a threshold 30 percent probability of severe wind or hail and/or a 10 percent chance of a tornado during the Day 1 period. For Days 2 and 3, the “Enhanced” risk category will denote a 30 percent total severe probability. The Moderate and High risk thresholds will remain essentially unchanged.

Current:

1. See Text
2. Slight (SLGT)
3. Moderate (MDT)
4. High (HIGH)

Proposed:

1. Marginal (MRGL) – replaces the current SEE TEXT and now is described with Categorical line on the SPC Outlook.
2. Slight (SLGT)
3. Enhanced (ENH) – will replace upper-end SLGT risk probabilities, but is not a MDT risk
4. Moderate (MDT)
5. High (HIGH)

The examples below juxtapose the proposed (left) and the current (right) outlook graphics for the marginal (MRGL) and enhanced (ENH) categories as opposed to the current slight (SLGT) category and SEE TEXT labels.

2011/06/01 1300Z Day 1 Outlook Preview Graphics
Proposed 2011/06/01 1300Z Day 1 Categorical Outlook (Proposed Areal Outline Product Example|KMZ|SHP) (Top)
2011/06/01 1300Z Day 1 Outlook Graphics
Current 2011/06/01 1300Z Day 1 Outlook Graphics (Current Areal Outline Product) (Top)

The examples below juxtapose the proposed (left) and the current (right) outlook graphics for the marginal (MRGL) and enhanced (ENH) categories as opposed to the current slight (SLGT) category.

2013/02/10 1630Z Day 1 Outlook Preview Graphics
Proposed 2013/02/10 1630Z Day 1 Categorical Outlook (Proposed Areal Outline Product Example|KMZ|SHP) (Top)
2013/02/10 1630Z Day 1 Outlook Graphics
Current 2013/02/10 1630Z Day 1 Outlook Graphics (Current Areal Outline Product) (Top)

The examples below juxtapose the proposed (left) and the current (right) outlook graphics for the marginal (MRGL) categorie as opposed to the current SEE TEXT labels which does not clearly define the geographical areas of concern.

2013/09/15 1630Z Day 1 Outlook Preview Graphics
Proposed 2013/09/15 1630Z Day 1 Categorical Outlook (Proposed Areal Outline Product Example|KMZ|SHP) (Top)
2013/09/15 1630Z Day 1 Outlook Graphics
Current 2013/09/15 1630Z Day 1 Outlook Graphics (Current Areal Outline Product) (Top)

The examples below juxtapose the proposed (left) and the current (right) outlook graphics for the all categorie as opposed to the current SLGT/MDT/HIGH.

2011/04/27 1630Z Day 1 Outlook Preview Graphics
Proposed 2011/04/27 1630Z Day 1 Categorical Outlook (Proposed Areal Outline Product Example|KMZ|SHP) (Top)
2011/04/27 1630Z Day 1 Outlook Graphics
Current 2011/04/27 1630Z Day 1 Outlook Graphics (Current Areal Outline Product) (Top)

The examples below juxtapose the proposed (left) and the current (right) outlook graphics for the marginal (MRGL) categorie as opposed to the current SEE TEXT labels which does not clearly define the geographical areas of concern.

2011/05/21 1730Z Day 2 Outlook Preview Graphics
Proposed 2011/05/21 1730Z Day 2 Categorical Outlook (Proposed Areal Outline Product Example|KMZ|SHP) (Top)
2011/05/21 1730Z Day 2 Outlook Graphics
Current 2011/05/21 1730Z Day 2 Outlook Graphics (Current Areal Outline Product) (Top)

Below is an example of a proposed Public Severe Weather Graphic that includes the new categories. This graphic is enlarged on the area of greatest risk and designed for use by media partners and social media.

Proposed 2011/04/27 1630Z Public Severe Weather Outlook Graphic
Proposed 2011/04/27 1630Z Public Severe Weather Outlook Graphic (Top)

Q: Why is the SPC proposing to do this?

A: A primary goal of these changes is to bring better consistency to the risks communicated in SPC outlooks, from the short-range Day 1 outlooks through the extended range Day 4-8 outlooks. The changes are being made based on customer feedback and to better meet their needs.

Example: Currently, a 10 percent tornado probability including a risk of a significant tornado (>=EF2) is categorized as a Slight Risk. This is the same category used for a “low end” 15 percent risk of severe thunderstorm wind and hail events. In the new scheme, a 10 percent tornado probability that includes the chance of significant tornadoes would be categorized as an Enhanced Risk.

In addition, “See Text” does not currently convey a threat area, due to the lack of a contour in any “See Text” categorical forecast. And the current “Slight Risk” category covers too broad a range of severe weather probability values.

Q: Are there cases where the current categories will change based on the underlying severe weather probabilities?

A: The thresholds for traditional risk categories are essentially unchanged but there is some refinement in the underlying definitions to remain consistent with evolving trends in severe weather reporting. These refinements would only impact a couple of Day 1 tornado and severe wind outlooks during any year. A 15 percent tornado probability without a threat of an EF-2 or greater tornado at Day 1 will qualify as an Enhanced Day 1 tornado risk as opposed to the current scheme where it is a Moderate Day 1 Tornado Risk. Likewise, a 45 percent severe thunderstorm wind probability without a significant threat at Day 1 will qualify as an Enhanced Day 1 wind risk as opposed to the current scheme where it is a Moderate Day 1 wind risk.

Q: Why not a more comprehensive overhaul of all categorical outlook words (i.e. SLGT, MDT, HIGH)?

A: The categorical words Slight, Moderate and High have been used by SPC for nearly 35 years and are generally understood by the weather risk communication community. Making measured changes to the current system, we believe, is more effective than a wholesale change. These measured changes include: 1) moving to de-emphasize the specific words; and 2) working to communicate the level of risk to the public in multiple ways. This includes numerical risk categorization, appropriate colors to indicate severity, and strategic use of icons and symbols. Social scientists have encouraged us to communicate on multiple levels and not just with a single word, label or category.

Q: When will this change occur?

A: A 45-Day Public Comment Period regarding the proposed outlook changes ended on June 17, 2014. After assessing the feedback and incorporating any needed adjustments, a Service Change Notice will be issued at least 75 days prior to the implementation of changes to the outlook categories.
Updated: Service Change Notice 14-42 has been issued. The change will be effective Wednesday, October 22, 2014, at 1500 UTC.

Q: What role did social science play in making this change?

A: The NWS has a strong commitment to engaging the social sciences in evolving our services, and this community has helped inform our decision making for this change.


Technical Details of the Proposed SPC Day 1-3 Outlook Change

The proposed effective date is mid-to-late September 2014. NWS Storm Prediction Center (SPC) Day 1, Day 2, and Day 3 Convective Outlooks for the CONUS will include two new risk categories.

The addition of the new risk categories is based on customer feedback and the need to provide better consistency with other NWS products. Examples of these Outlooks (using historical data), are depicted below.

“MARGINAL” replaces the current SEE TEXT used in these products.

“ENHANCED” is an additional category to delineate areas of risk in the high end of the current SLIGHT risk, but below MODERATE risk.


Click on the links below to view the section:

Proposed Product Text Example Day 1 Outlook Descriptions Day 2, 3 Outlook Descriptions Product IDs To Be Changed

Below is an example of the Convective Outlook text product containing “MARGINAL” (MRGL) and “ENHANCED” (ENH) risk area delineations and Summary section. (Top)

   DAY 1 CONVECTIVE OUTLOOK
   NWS STORM PREDICTION CENTER NORMAN OK
   0110 AM CDT WED APR 27 2011
    
   VALID 271200Z - 281200Z
   
   ...THERE IS A HIGH RISK OF SVR TSTMS OVER PORTIONS OF NRN
   MS...AL...FAR NWRN GA AND SRN MIDDLE TN...
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER MUCH OF CNTRL AND NRN MS
   AND AL...NWRN GA...MUCH OF TN AND KY...WRN CAROLINAS...
   
   ...THERE IS AN ENH RISK OF SVR TSTMS FROM PARTS OF THE LOWER MS
   VALLEY TO THE UPPER OH VALLEY/CNTRL APPLACHIANS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GULF COAST TO THE
   NRN APPALACHIANS...
   
   ...THERE IS A MRGL RISK OF SVR TSTMS FROM THE LOWER MS VALLEY TO THE
   EAST COAST...
   
   ...SUMMARY...
   AN OUTBREAK OF TORNADOES AND DAMAGING WINDS IS EXPECTED TODAY THROUGH
   THIS EVENING OVER PORTIONS OF NORTHERN MS/AL...TN AND KY. FAST-MOVING
   SUPERCELLS WILL BE CAPABLE OF LONG-TRACKED STRONG TO VIOLENT
   TORNADOES.
   
   ...SYNOPSIS...
   (The rest of the discussion remains unchanged.)


With the addition of “MARGINAL” and “ENHANCED” categories, the new categorical Day 1-3 Outlooks will include contours for up to six (6) categories as follows: (Top)

Day 1: 
   a. General Thunderstorms
      - 10% or greater probability of non-severe or near severe thunderstorms. 

   b. Severe Category 1 - Marginal 
      - 2% or greater tornado probability, or 
      - 5% or greater severe hail or severe wind probability.

   c. Severe Category 2 - Slight 
      - 5% or greater tornado probability, or 
      - 15% or greater severe hail or severe wind probability.

   d. Severe Category 3 - Enhanced 
      - 10% or greater tornado probability, or 
      - 30% or greater severe hail or severe wind probability.

   e. Severe Category 4 - Moderate 
      - 15% or greater tornado probability AND 10% or greater probability 
        of an EF2+ tornado, or
      - 30% or greater tornado probability, or
      - 45% or greater severe wind probability AND 10% or greater 
        probability of a wind gusts 75 mph or greater, or
      - 45% or greater severe hail probability AND 10% or greater 
        probability of hail 2 inches or greater in diameter, or
      - 60% or greater severe wind probability, or
      - 60% or greater severe hail probability.

   f. Severe Category 5 - High 
      - 30% or greater tornado probability AND 10% or greater probability 
        of an EF2+ tornado, or
      - 45% or greater tornado probability, or
      - 60% or greater severe wind probability AND a 10% or greater 
        probability of a wind gust 75 mph or greater.

Day1 probability to categorical conversion table
Day 1 Outlook Probability to Category Conversion Table


Days 2 and 3: (Top)
   a. General Thunderstorms
      - 10% or greater probability of non-severe or near severe thunderstorms.

   b. Severe Category 1 - Marginal 
      - 5% or greater total severe probability.

   c. Severe Category 2 - Slight
      - 15% or greater total severe probability.

   d. Severe Category 3 - Enhanced 
      - 30% or greater total severe probability.

   e. Severe Category 4 - Moderate 
      - 45% or greater total severe probability AND 10% or greater 
        probability of an EF2+ tornado, a wind gust 75 mph or greater, or 
        hail 2 inches or greater in diameter, or
      - 60% or greater total severe probability (Day 2 only).

   f. Severe Category 5 - High (Day 2 only) 
      - 60% or greater total severe probability AND 10% or greater 
        probability of an EF2+ tornado or a wind gust 75 mph or greater.
Day2 probability to categorical conversion tableDay 2 Outlook Probability to Category Conversion Table Day3 probability to categorical conversion tableDay 3 Outlook Probability to Category Conversion Table

The following products reflect the changes: (Top)

   WMO Header    AWIPS ID    Description
   ACUS01 KWNS   SWODY1      Day 1 Convective Outlook Discussion
   WUUS01 KWNS   PTSDY1      Day 1 Convective Outlook Areal Outline
   PGWE46 KWNS   RBG94O      Day 1 Red Book Graphic Categorical Outlook
   LDIZ17 KWNS               Day 1 NDFD Categorical Outlook
   ACUS02 KWNS   SWODY2      Day 2 Convective Outlook Discussion
   WUUS02 KWNS   PTSDY2      Day 2 Convective Outlook Areal Outline
   PGWK48 KWNS   RBG99O      Day 2 Red Book Graphic Categorical Outlook
   LDIZ27 KWNS               Day 2 NDFD Categorical Outlook
   ACUS03 KWNS   SWODY3      Day 3 Convective Outlook Discussion
   WUUS03 KWNS   PTSDY3      Day 3 Convective Outlook Areal Outline
   PGWI47 KWNS   RBG98O      Day 3 Red Book Graphic Categorical Outlook
   LDIZ37 KWNS               Day 3 NDFD Categorical Outlook

   The "points" products (PTSDY1, PTSDY2, and PTSDY3) will include new labels "MRGL" (Marginal)
   and "ENH" (Enhanced).

 

So as you can see, there is A LOT of thinking and data that goes into communicating severe weather! However, I for one wonder if the two extra categories will be confusing for the public? Or do you think the new way in labeling severe weather threats will help you better to understand the risk factors involved in what might lie ahead? In my years as a meteorologist I have seen on several occasions very bad severe weather outbreaks when we were under just a “Slight Risk” and I have seen busts when we have been under a “Moderate” or “High” risk. Of course, I know the weather is not an exact science, but maybe more categories for severe weather outlooks could better describe the risk factors? I’m curious to hear your thoughts!

-Kyle

Total Lunar Eclipse Wednesday Morning!

The sun and the moon will literally do battle tomorrow morning during the morning hours with a total lunar eclipse set to dazzle eyes all across the country. This is the second full lunar eclipse that we will see this year, two more are expected next year as well with one in April and September of 2015

The partial eclipse will begin shortly after 5 AM Wednesday morning with the total eclipse beginning around 6:25 AM. This will take place with the moon setting in the western horizon and should make for quite the spectacle since the moon will appear bigger being so close to  the horizon.Here is a video with more details!

And it looks as if mother nature will cooperate with clearing skies expected overnight here in West Central Ohio! Here is a look at two short-term models showing clear skies around 7 AM Wednesday morning!

HRRR Cloud Cover RPM Satellite

Again, the partial eclipse will begin around 5:15 AM with the total eclipse starting at 6:25 AM. Happy viewing!

-Kyle

Welcome To October’s Temperature Roller Coaster!

Are you ready? It’s that time of year! The time of the year when mother nature will REALLY begin to have a hard time making up her mind on whether or not she wants to hang on to summer, or dive in head first into Fall.

The ride begins on Thursday with West Central Ohio expected to warm into the low 80’s in what will very much feel like a Summer day. But the warmth will be very short-lived thanks to a strong cold front slated to move through on Friday. The front will begin to move in from the West on Thursday night bringing scattered showers to the region into the pre-dawn hours on Friday with the front expected to move through sometime early afternoon during the day.

Kyle RPM 12KM Futurecast

As of now the chance for severe weather with this front is very low. Nonetheless, I’ll still be watching Friday early afternoon as the front passes through for the small chance one or two storms along it become severe.

DAY 2 OUTLOOK

As of now the big reason why I’m not very concerned with severe weather is due to the fact that there won’t be much CAPE in the region as the front moves through early Friday afternoon. Again, CAPE is the atmospheres potential to rapidly produce storms with strong updrafts to fuel them. Almost no sunshine is forecasted for Friday, that allows ample cloud cover to help keep the atmosphere stable. ALSO, the area of low pressure seen in the above picture will be pulling pretty far north and occluding from the main cold front. This process helps to cut off low-level moisture (higher dew points) from making it this far north. At best, dew points on Friday will make it into the low 60’s, that’s not all that impressive for severe weather.

There will be high amounts of wind shear present over the region as the cold front moves through though.

NAM SHEAR

This wind shear along the front will help to initiate widespread rain through the Great Lakes most of the day Friday. Wind shear (a change in wind direction or speed in the atmosphere) is a lifting process. This lift along the cold front will no doubt trigger rain, but without that extra ummph from instability and higher CAPE, I would be surprised if we just saw nothing more than regular showers and thunderstorms with occasional higher wind gusts during the day. And if you’re thinking about heading to a game Friday night. The showers should be beginning to taper off by kick off but be sure to dress warm and bring the umbrella just in case!

Here’s the biggest news! It’s looking like temperatures on Saturday will STRUGGLE to break 50 degrees behind this strong cold front. My forecast right now has us at 52 for the high, but honestly, I wouldn’t be surprised if we didn’t even make it out of the 40’s! You can see the COOL air in this model, the time shown is Saturday afternoon.

NAM Temps

As I mentioned earlier, I’m not that concerned about Friday. But you know I’ll have my eye on it regardless! And if you haven’t yet, please check out our FREE weather app! You can always keep an eye on storms with our interactive radar along with receive automatic updates on watches and warnings!

APP PIC

-Kyle

Beach Trip With A Baby!

This past week my wife and I took a trip to Ocean Isle Beach, North Carolina with our 7 month old little girl. First off, if you’re wondering where Ocean Isle Beach is, it’s about 30 miles or so to the north of Myrtle Beach just over the border into North Carolina.

OIB

Of course we were a little bit nervous, but our little girl, August was a champ on the trip down! Packing a beach trip for a baby adds all kinds of new elements to think about when getting ready. But out of all the things we brought, this baby beach tent may have been the most clutch. It worked out perfectly to help shade her from the sun and get her out of the sand when she was tired :)

Beach tent

 

The weather was kind of what you might expect for late September, there were a few days of sun and 80 degree weather followed by a few days of showers and temperatures in the upper 60’s. But that didn’t stop us from getting out to the beach on most days to enjoy some nice time as a family. As you can see in the picture below, someone was pretty pumped to be at the beach.

August

It’s always great to get away for a bit, but we’re glad to be back. Here are a few more shots from our trip.

meg feeds august

Beach

-Kyle

 

 

 

Could We See The Aurora Borealis Friday And Saturday?

Over the past couple of days we have seen a lot of activity from our sun in the form of powerful solar flares. With these solar flares the sun can release what are called “Coronal Mass Ejections” or CME’s that can hurl VERY hot plasma towards earth and effect everything from satellites circling the earth to our electrical grids here on the surface.

Here is a nice picture from the Solar Dynamics Observatory of a flare that was produced on Wednesday that was pointed right at the earth.

Solar Flare

Thanks to the flare shown above and a previous (weaker) flare earlier in the week, two CME’s are now headed near earth and could potentially affect us in a variety of ways into the upcoming weekend. When a CME (or in this case two CME’s) come near earth they interact with our planets magnetosphere causing geomagnetic storms which increase electric current.

Because of this the National Weather Service’s Space Weather Prediction Center has issued a G3 Geomagnetic Storm Watch for September 13th (Saturday) So what is a G3 geomagnetic storm you might ask? Here is the criteria for a G3 storm per the Space Weather Prediction Center. (here is the entire scale for geomagnetic storms)

G3 STRONG Geomagnetic Storm

Power systems: voltage corrections may be required, false alarms triggered on some protection devices.

Spacecraft operations: surface charging may occur on satellite components, drag may increase on low-Earth-orbit satellites, and corrections may be needed for orientation problems.

Other systems: intermittent satellite navigation and low-frequency radio navigation problems may occur, HF radio may be intermittent, and aurora has been seen as low as Illinois and Oregon (typically 50° geomagnetic lat.)**.

OK, did you get all of that? The sun can potentially cause A LOT of problems here on earth with these types of solar storms. THANKFULLY this time around we’re expected to be just fine.

Now on to the title of this post! Will we see the Aurora Borealis because of this? The short answer is maybe! In past events similar to this the dazzling northern lights have been known to reach this far south. The best chance to catch a glimpse of them would definitely be Friday and Saturday night, at any point during the night just look north!

If you’re interested in more on solar storms and how they have impacted earth here are two excellent reads about the Carrington Event Of 1859 and The 1989 Blackout of Quebec BIG thanks to our Chief Engineer, Fred Vobbe for pointing out these significant events!

-Kyle

Wednesday West Central Ohio Severe Weather UPDATE

9/9/2014

I’m still watching for the potential for severe thunderstorms Wednesday afternoon and evening here in West Central Ohio that could include damaging winds and the threat for an isolated tornado.

All of Northwest Ohio continues to be under a “Slight Risk” Wednesday afternoon and evening as a strong cold front moves into the region.

DAY 1 OUTLOOK

In my post yesterday I talked extensively about shear and CAPE and how these two severe weather parameters could influence storms on Wednesday. Here’s the blog post I won’t re-hash much on the dynamics of the system today because not that much has changed. The shear will be in place with this storm to help aid severe weather but the question continues to be whether or not we’ll get enough instability or CAPE during the afternoon and evening.

As of this writing, severe storms are ongoing over parts of the midwest and will race eastward overnight into the early afternoon hours tomorrow. The latest models show that the remnants of these storms will spread clouds, showers and thunderstorms over West Central Ohio into the early afternoon hours. This would be GOOD news since it will drastically lower our severe weather chance by keeping our atmosphere free of ample mid day sunshine thus keeping us more stable.

Wed 2 PM Future

Notice in the picture above that as the remnants of Tuesday’s storms are moving through West Central Ohio, the main cold front will still be well off to our west. It’s the time period between when the first round of showers and thunderstorms move through  and when the actual cold front brings the second (potentially stronger) round of storms into West Central Ohio when we’ll see if we can get some clearing.

Wed 4 PM Future

By 3 or 4 in the afternoon on Wednesday all eyes will be along the cold front to see the severity of storms that develop. If the area I have highlighted in red gets some sunshine and destabilization late afternoon then it’s very possible we could be looking at a pretty good severe weather set up. For now, our Futurecast model shows the main front moving through late evening with the better chance for widespread damaging wind probably staying to our south and west where the better instability will likely develop (CAPE) during the day.

Wed 10 PM Future

But as I mentioned in my previous blog post, it doesn’t take much CAPE at all in a situation like tomorrow’s to generate severe thunderstorms thanks to strong wind shear that will be in place. Here are my main concerns Wednesday into the 4PM to 11PM range as the strong cold front moves in.

SEVERE HAZARD OUTLOOK NEW

Damaging wind is the biggest concern along with the chance for an isolated tornado. There could be heavier downpours possible in some of the storms too leading to over an inch of rain in some locations into late Wednesday evening.

Kyle Future Rainfall

Be sure to keep up with the storms on our new weather app as well, it’s a GREAT tool for tracking storms.

APP PIC

I’ll be sure to keep you updated, i’ll have the latest tonight as well on Your News Now at 10 and 11!

-Kyle

 

Severe Storms Possible Late Wednesday For West Central Ohio

9/8/2014

A strong cold front will move through the region late Wednesday bringing the possibility for severe weather including damaging wind and the threat for an isolated tornado.

The set up is one that is definitely showing that we’re nearing the changing of the seasons with a MUCH cooler air mass slated to move into West Central Ohio. The system will really gain steam on Tuesday with severe weather a good possibility through Nebraska, Iowa, Southern Minnesota and parts of Wisconsin.

Tuesday Future

The cold front will continue to push east on Wednesday shifting the threat for severe weather into the Southern Great Lakes.

DAY 2 OUTLOOK

Some unseasonably strong upper level wind support will accompany this system as it moves in late Wednesday afternoon and Wednesday evening. If you read this blog you have probably heard me talk about “wind shear” and “CAPE” quite often, both being important contributors to severe weather potential. In Wednesday’s case, there will be pretty high wind shear for this time of year with CAPE values that are still in question. Here’s the set up:

Wind Shear

As the cold front nears on Wednesday evening it will have pretty good upper level wind support to help maintain storms that develop along the front. Most forecast models agree with each other and show wind shear values high enough to warrant severe weather potential here in West Central Ohio. Wind shear is either the change in wind SPEED with height or the change in wind DIRECTION with height in the atmosphere. This change of wind through the atmosphere is crucial to building and maintaining severe thunderstorms. Here is a look at where the highest wind shear will be Wednesday evening, the higher shear values are where the darker colors are in this map.

NAM SHEAR

I also look at very low-level wind shear and the chance for the atmosphere to generate LOW level circulation in thunderstorms, this is called Helicity. Helicity values from the surface up too about 1 kilometer in the sky are moderately high Wednesday evening. This is a main reason we could see an isolated tornado or two somewhere in NW Ohio late Wednesday. While our helicty values are progged to be higher than normal, the highest low-level helicity is probably going to stay to our north closer to the are of low pressure moving through the Northern Great Lakes.

NAM HELICITY

CAPE

We know that good wind shear will be in place along the front as it moves through West Central Ohio Wednesday, but the CAPE is still in question. CAPE, or, Convective Available Potential Energy is the energy in the atmosphere that is used to rapidly develop thunderstorms. Basically,The more sunshine we get on Wednesday= The higher CAPE values we’ll have to fuel potential severe weather. If you can get a lot of instability (high CAPE) AND high wind shear along a strong cold front then look out! Thankfully, our CAPE will probably be on the low side here in West Central Ohio. But that’s still not to say we’ll completely dodge the bullet.

Most forecast models are showing relatively low CAPE late Wednesday including the GFS shown below. Notice in the graphic that the highest CAPE (which is still pretty low) is off into Southern Indiana and Illinois by about 8 PM Wednesday.

GFS CAPE

Here is a look at the NAM model at the same time (this one has been a bit of an outlier)

NAM CAPE

IF, and that’s a BIG if, we can get CAPE values Wednesday afternoon as the NAM is indicating then we have the potential to see a pretty substantial severe weather outbreak for this time of year. Thankfully, as of now, I don’t think that is going to happen. Here’s why:

Strong to severe thunderstorms will be ongoing through the midwest into Tuesday night. These storms will weaken and eventually move east towards us here in West Central Ohio. These storms will spread considerable cloudiness over NW Ohio into Wednesday morning/early afternoon.

Future Wednesday Morning

Notice in the above picture that the storms will be racing out ahead of the better forcing and lift along the cold front by Wednesday morning, along with a loss of daytime heating, this will definitely weaken these storms below severe limits. IF we can stay mostly cloudy with remnant showers from Tuesday’s storms on Wednesday, our atmosphere has a good chance at staying pretty stable (Low CAPE). This is definitely what I’ll be watching most as this cold front nears.

As of now, my forecast is calling for low CAPE and thus a lower severe threat late Wednesday. However, with such high shear values in place, it doesn’t take much destabilization to fire up storms. With that in mind the biggest threat is damaging winds in the 6PM to Midnight timeframe Wednesday evening. Because of pretty good wind shear and low-level helicity, an isolated tornado can’t be ruled out either. Here is a look at how I think the severe weather threat will break down.

SEVERE HAZARD OUTLOOK NEW

These are just my initial thoughts right now. We still have two days until these storms arrive so I will be sure to keep up on the latest forecasts and keep you updated! ALSO, if you haven’t yet, please check out our FREE weather app. With live radar and up to date watches and warnings it’s a wonderful tool to have with severe weather approaching.

APP PIC

Stay tuned!

-Kyle

 

 

 

 

 

 

A Hot Friday With Thunderstorms To Cool Us Down

9/4/2014

Tomorrow may be one of our last chances to reach 90 degrees for the remainder of the summer thanks to a cold front that will pass through late tomorrow evening here in West Central Ohio. During the day temperatures will easily warm into the upper 80’s along with continued dew points hovering around 70 degrees, that means another hot and muggy day.

But the warmth will NOT last into the weekend thanks to a cold front expected to move in by the end of the day Friday. With this front moving into such a hot and muggy environment, showers and thunderstorms are expected to develop by the late afternoon hours across parts of Indiana and Michigan. Based on the latest forecast models, these storms will track East/Southeast into West Central Ohio by the late evening hours. Here is a look at Futurecast by 8 PM Friday evening.

8 PM Future

This will likely end up being a broken line of showers and thunderstorms moving through West Central Ohio in the 8PM to Midnight timeframe. Headed out to a football game tomorrow night? Be sure to keep an eye to the sky!

The good news is that these storms should mostly stay BELOW severe limits. Isolated wind damage is possible, but the overall severe threat will be low thanks to a general lack up upper wind support (wind shear) as these storms move through. Here is a look at some of that shear, notice the higher shear values (darker blue and purple) stay WELL north of the area into Friday afternoon and evening.

Shear Friday

Without this wind shear support the storms that develop along this cold front will have a hard time maintaining themselves. Good wind shear allows storms to develop longer lasting updrafts that can lead to stronger storms. A few of these storms could be on the strong side, but the overall threat remains low at this time. An isolated damaging wind gust is possible along with possible flooding where slower moving storms set up.

SEVERE HAZARD OUTLOOK NEW

Even though the severe threat is low, there is a good chance thunderstorms will be in the region. If you’re headed to a football game be sure to stay up to date on the latest forecasts and radar. There is no better way to do that than with our Storm Authority Weather App which can be downloaded for free!

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-Kyle

Will We Hit 90 Degrees This Summer?

We still have yet to hit 90 degrees this summer and now that were into the month of September we’re really beginning to run out of chances! The good news it that if you do want a 90 degree day we have a shot later this week on Friday before another cold front moves through bringing a cool down into the weekend.

Temperatures AND dew points will continue to rise here on Thursday with highs creeping into the mid 80’s, but more importantly, dew point readings potentially into the low 70’s. That will make it feel MUCH more muggy outside on Thursday.

Future Dew Points

We’ll hang onto those high dew points on Friday with temperatures expected to top out near 90 degrees! As of now, my forecasted high is at 89 degrees. But I would not be surprised if a few locations here in West Central Ohio were able to reach 90! Here’s a look at projected temperatures by early Friday afternoon.

Future Temperatures

All this heat and humidity will be wiped away thanks to a cold front late Friday with a round of showers and thunderstorms moving through. As of now, Futurecast shows the cold front moving through late Friday afternoon into Friday evening. And with a hot and humid air mass in place, there is a good chance scattered showers and thunderstorms will be present late in the day.

Kyle RPM 12KM Futurecast

Any time a cold front is moving through a primed air mass like the one that will be in place on Friday, I naturally look to see if there will be any threat for severe weather. CAPE will be high here in West Central Ohio on Friday thanks to the heat and humidity, meaning that there will be plenty of POTENTIAL energy to work with as the front moves through. CAPE values by late Friday afternoon will likely easily exceed 2,000 J/Kg which is plenty to develop scattered showers and thunderstorms along the cold front moving through.

CAPE Friday

So we’ll have the CAPE but will we have the wind shear to back it up? The short answer is NO.

Most of the higher wind shear will be present well north of the cold front moving through. When you get the combination of high wind shear, high CAPE and a trigger (cold front) you usually have a legitimate threat for severe weather. On Friday afternoon and evening we’ll have 2 of the 3. Here is a look at the highest wind shear values late Friday afternoon, notice the highest wind shear is WELL north of the Southern Great Lakes.

GFS Friday Shear

Without the wind shear present we’ll still get thunderstorms late Friday thanks to the passing front and high CAPE, and sure, a few of them could produce some isolated damaging wind. But overall, the threat for severe weather looks pretty low thanks to very low wind shear. Either way it is still expected to be potentially stormy Friday night, so if you’re planning on heading out to a game be sure to keep an eye to the sky! You can also download our NEW weather app so track any storms moving through on your phone.

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I’ll be sure to keep you updated!

-Kyle

 

Severe Weather For Parts Of The Midwest Labor Day Weekend

We’re in for a change in our weather pattern as we head into the Labor Day weekend, and unfortunately it’s looking like a pretty active weather period can be expected in the Midwest through early next week.

A warm front lifting out of the south on Friday will signal the change. This front will bring a return of hotter and more humid conditions into the upcoming weekend. But there is good news! Even with the front in the region on Friday, it does look as if we’ll stay dry here in West Central Ohio for the first Football Friday Night of the season. We’ll just have to deal with a little more heat and mugginess.

After a dry first half of our Saturday, ample moisture building in out of the south will bring an increased chance for showers and thunderstorms into the evening and overnight hours. These showers and thunderstorms are NOT expected to be severe but they could bring with them some heavy rain into Sunday morning.

Saturday Rain

Once that system moves off to our east on Sunday we’ll see a gradual decrease in rain and clouds by the afternoon and evening. My attention will then shift out West where a better chance for severe weather could set up Sunday and Monday.

The National Weather Service already has an area highlighted on Sunday in anticipation of a severe weather outbreak.

Sunday Outlook

A couple of very key ingredients are expected to come together on Sunday in the region highlighted above that will help to spark severe storms.

1) Wind Shear

High wind shear is expected over Nebraska, Iowa and Minnesota on Sunday afternoon. Wind shear is basically a change in DIRECTION or SPEED in wind as you go higher up into the sky. The more there is a change in wind direction or speed from the surface and up through the atmosphere, the more chance you have for thunderstorms that will be long-lasting and able to maintain themselves for hours at a time.

Sunday Shear

2) Instability

High CAPE, or, Convective Available Potential Energy is expected as well in this region on Sunday. The higher the CAPE values, the more primed the atmosphere is for any POTENTIAL thunderstorms.

Sunday CAPE

3) A Trigger

Without some sort of trigger, we could have all the CAPE in the world and it could still be a sunny day. In this case however, the trigger will be a strong cold front pushing through the Midwest that will be able to tap into high CAPE values and good wind shear likely triggering a round of severe weather.

By Monday all of this activity will push east and closer to us here in West Central Ohio. The same ingredients I highlighted above will be in play on Labor Day. As the aforementioned cold front continues to push east it will bring the focus for potential severe weather into parts of Wisconsin, Illinois and Indiana where the best CAPE and Shear will be on Monday. Where you see the cold front, high shear and CAPE come together, that’s where the chance for severe storms will be.

In the graphic below I have circled an area where shear will be high, this is also the region where CAPE values will exceed 2,000 J/kg. Both shear and CAPE will NOT be as high on Monday as it was on Sunday further west. Notice that Western Ohio is not included in the area I have circled.

Monday Shear

Here is a look at the CAPE on Monday.

Labor Day CAPE

This set up certainly catches my eye especially since it will be closer to West Central Ohio on Monday. As of now it looks as if strong to severe storms will develop late Monday afternoon over Southern Wisconsin and Illinois and then push east into the evening. By the time they would reach West Central Ohio they will be outrunning both better CAPE and shear in the atmosphere. Nonetheless, this is still something to watch late Monday. This system is still four days away and if it speeds up (which is a possibility) that would shift the focus for severe weather closer to home. This is something to keep an eye on over the weekend, I’ll be sure to keep you updated!

-Kyle

If you haven’t yet, be sure to download our FREE Weather App! I use it all the time for tracking storms when I’m not in the office.

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