All Weather News

Severe Weather Threat Ramps Up

18 May 2013, 7:13 am

Lovely Weather for a Duck
Thanks to Julie Hickstein for the picture below out of the Twin Cities from Friday. The soggy Friday weather was enough to make even this duck a little weird. Can you spot it?

Stormy Weather Ahead?
Billie Holiday once sang: “Don’t know why there’s no sun up in the sky. Stormy Weather.” Of course she kept singing and it turned out that it had been raining since her man and her weren’t together anymore… I’ve had this song stuck in my head over the last several days while looking at weather maps. Take a look at NOAA’s HPC 5 day precipitation forecat below. A slow moving/waterlogged Pacific storm will wind up over the middle part of the country through next week and keep shower and thunder activity in place over some of the same areas over the next several days. Some may end up with 2″ to 4″+ by the time this storm wrings itself out next week.

 

 

 

Severe Thunderstorm Threat

 

 

This vigorous low pressure system will help to envigorate strong to severe storms this weekend across parts of the Midwest. Hail, high winds and isolated tornadoes can’t be ruled out. Stay tuned to local forecasts if you live in highlighted and surrounding areas this weekend. Keep in mind that highlighted risk areas will likely change through the weekend as more information becomes available…

 

 

 

 

Saturday’s Threat (text below via SPC):

 

 

   ...PLAINS...
   FRIDAY EVENING WATER VAPOR IMAGERY SHOWS A LEAD SHORTWAVE TROUGH
   OVER SRN NM AND THIS FEATURE IS FORECAST TO MOVE INTO CNTRL KS-OK BY
   EARLY-MID AFTERNOON.  DESPITE IMPLIED SUBSIDENCE IN ITS WAKE...THE
   APPROACH OF THE LARGER SCALE TROUGH AND ASSOCIATED HEIGHT FALLS
   /FORCING FOR ASCENT/ WILL OVERSPREAD THE HIGH PLAINS DURING THE
   AFTERNOON-EVENING.  BENEATH THE STOUT EML...HIGH QUALITY BOUNDARY
   LAYER MOISTURE SAMPLED BY RAOBS OVER THE SRN PLAINS FRIDAY EVENING
   /15-16 G/KG 100MB MEAN MIXING RATIO/...WILL LEAD TO DEWPOINTS
   RANGING FROM THE LOWER 60S OVER THE DAKOTAS TO THE UPPER 60S AND
   LOWER 70S FARTHER S OVER OK/KS BY MID AFTERNOON.  STRONG DIABATIC
   HEATING ALONG THE DRYLINE WILL CONSIDERABLY WEAKEN AN INITIALLY
   STOUT CAP BY MID-LATE AFTERNOON.  VERY STEEP MID LEVEL LAPSE RATES
   IN EXCESS OF 8-9 DEG C/KM IN COMBINATION WITH THIS RICH MOISTURE
   WILL CONTRIBUTE TO MODERATE INSTABILITY OVER PARTS OF THE NRN PLAINS
   TO EXTREME INSTABILITY /4000-5000 J/KG MLCAPE/ OVER PARTS OF KS INTO
   NWRN TX. 

   ONCE THE CAP IS ERODED IN POCKETS ALONG THE DRYLINE...EXPLOSIVE
   UPDRAFTS WILL RAPIDLY BECOME SEVERE AND INITIALLY FAVOR LARGE TO
   VERY LARGE HAIL AND DMGG WINDS.  SUFFICIENT DEEP LAYER SHEAR
   /RANGING FROM AROUND 30 KT FROM NWRN TX TO WELL INTO THE SUPERCELL
   RANGE FROM KS NWD/ WILL PROMOTE DISCRETE SUPERCELLS AS THE EARLY
   CONVECTIVE MODE.  BY THE 00Z-04Z PERIOD...STRONGER LOW LEVEL MASS
   RESPONSE IN THE FORM OF A STRENGTHENING LLJ E AND SE OF THE KS/CO
   LOW OVER PARTS OF WRN KS AND WRN OK...WILL ACT TO ENLARGE HODOGRAPHS
   /200-500 M2/S2 EFFECTIVE SRH/ DURING THIS TIMEFRAME.  AS A
   RESULT...SUPERCELL TORNADO POTENTIAL APPEARS HIGHEST DURING THE
   EVENING WITH PERHAPS A STRONG TORNADO OR TWO OCCURRING.  UPSCALE
   GROWTH MAY EVENTUALLY OCCUR WITH ANY PERSISTENT OR REGENERATIVE
   CLUSTER OF SUPERCELLS WITH A LINGERING OVERNIGHT THREAT FOR A FEW
   TORNADOES AND DMGG WINDS.

 

 

 

 

 

Sunday’s Threat (text below via SPC):

 

 

   ...SRN AND CNTRL PLAINS/LOWER MO VALLEY...
   A NEGATIVELY-TILTED UPPER-LEVEL TROUGH WILL TRANSLATE EWD INTO THE
   SRN AND CNTRL PLAINS ON SUNDAY AS A MID-LEVEL JET MOVES EWD THROUGH
   THE CENTER OF THE TROUGH. AT THE SFC...A LOW IS FORECAST TO DEEPEN
   AND MOVE NEWD FROM CNTRL KS INTO ERN NEB AS A COLD FRONT ADVANCES
   SEWD ACROSS ECNTRL KS AND CNTRL OK. SFC DEWPOINTS TO THE EAST OF THE
   FRONT SHOULD BE IN THE MID TO UPPER 60S F WITH MODERATE TO STRONG
   DESTABILIZATION LIKELY ACROSS THE MODERATE RISK AREA BY MID TO LATE
   AFTERNOON. FORECAST SOUNDINGS AROUND MIDDAY SHOW A CAPPING INVERSION
   IN PLACE ACROSS MUCH OF THE WARM SECTOR. THE MODELS WEAKEN THE CAP
   BY 21Z ALLOWING FOR CONVECTIVE INITIATION ALONG AND AHEAD OF THE
   FRONT. STORMS SHOULD FIRST INITIATE IN NRN AND CNTRL KS...QUICKLY
   EXPANDING SWD INTO NRN AND CNTRL OK. AS STORM COVERAGE INCREASES
   DURING THE EARLY EVENING...A SEVERE PRODUCING MCS MAY ORGANIZE
   ACROSS ERN KS AND ECNTRL OK...MOVING ESEWD ACROSS THE MODERATE RISK
   AREA.

   FORECAST SOUNDINGS BY 21Z SUNDAY AT TULSA...OKLAHOMA CITY AND KANSAS
   CITY SHOW STRONG INSTABILITY WITH MLCAPE VALUES OF 2500 TO 3500
   J/KG. DEEP LAYER SHEAR IS FORECAST TO INCREASE DURING THE LATE
   AFTERNOON ACROSS THE MODERATE RISK AREA AS A MID-LEVEL JET MOVES
   INTO THE REGION FROM THE WEST. THIS COMBINED WITH 850 TO 500 MB
   LAPSE RATES EXCEEDING 8.0 C/KM SHOULD BE VERY FAVORABLE FOR
   SUPERCELLS WITH LARGE HAIL. HAILSTONES OF GREATER THAN 2 INCHES IN
   DIAMETER WILL BE POSSIBLE WITH THE MORE INTENSE SUPERCELLS. IN
   ADDITION...A LOW-LEVEL JET IS FORECAST TO BECOME FOCUSED BY EARLY
   SUNDAY EVENING FROM SW MO SWWD INTO ECNTRL OK. SUPERCELLS ON THE WRN
   EDGE OF THE LOW-LEVEL JET WILL HAVE A CHANCE TO BECOME TORNADIC WITH
   A CLUSTER OF TORNADOES POSSIBLE ACROSS THE MODERATE RISK AREA. THE
   GREATEST CHANCE FOR STRONG TORNADOES SHOULD EXIST ACROSS ECNTRL OK
   AND SE KS WHERE 0-3 KM STORM RELATIVE HELICITIES ARE FORECAST TO
   REACH 400 M2/S2 IN THE 00Z TO 03Z TIMEFRAME. DUE TO THE STRONG DEEP
   LAYER SHEAR...CELLS SHOULD REMAIN DISCRETE DURING MUCH OF THE EVENT.
   SUPERCELLS COULD ALSO PRODUCE SWATHS OF WIND DAMAGE. THE WIND DAMAGE
   THREAT COULD BECOME ENHANCED DURING THE EVENING IF A LINEAR MCS CAN
   ORGANIZE.

   ...MID-MO VALLEY/NRN PLAINS/UPPER MS VALLEY...
   SOUTH TO SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE NCNTRL U.S.
   SUNDAY AS AN UPPER-LEVEL TROUGH MOVES INTO THE SRN AND CNTRL PLAINS.
   AT THE SFC...A LOW IS FORECAST TO DEEPEN AND MOVE NEWD INTO THE
   MID-MO VALLEY DURING THE DAY. A MODERATELY UNSTABLE AIRMASS SHOULD
   BE IN PLACE BY MID AFTERNOON TO THE EAST AND NORTHEAST OF THE LOW
   ACROSS ERN NEB...SERN SD...IA AND SRN MN WHERE SFC DEWPOINTS MAY
   REACH THE LOWER TO MID 60S F. THE AIRMASS SHOULD BE UNCAPPED ACROSS
   MUCH OF THE REGION ALLOWING FOR CONVECTIVE INITIATION TO TAKE PLACE
   EARLY IN THE DAY. THUNDERSTORMS COULD BE ONGOING DURING THE MORNING
   ACROSS IA AND MN ALONG WRN EDGE OF THE LOW-LEVEL JET WITH ADDITIONAL
   THUNDERSTORM DEVELOPMENT TAKING PLACE BENEATH THE UPPER-LEVEL LOW
   EARLY SUNDAY AFTERNOON. SEVERAL CLUSTERS OF ORGANIZED THUNDERSTORMS
   APPEAR LIKELY TO PERSIST THROUGH THE AFTERNOON WITH MCS DEVELOPMENT
   POSSIBLE ACROSS PARTS OF THE REGION BY EVENING.

   FORECAST SOUNDINGS AT OMAHA AND DES MOINES AT 21Z SHOW MODERATE
   INSTABILITY WITH MLCAPE VALUES IN THE 2000 TO 3000 J/KG RANGE. THIS
   COMBINED WITH 30 TO 40 KT OF 0-6 KM SHEAR SHOULD SUPPORT SUPERCELL
   DEVELOPMENT WITH A THREAT FOR LARGE HAIL. HAILSTONES OF GREATER THAN
   2 INCHES IN DIAMETER WILL BE POSSIBLE WITH THE MORE DOMINANT
   SUPERCELLS MAINLY IN SE NEB AND SRN IA WHERE INSTABILITY IS FORECAST
   TO BE THE GREATER THAN IN AREAS TO THE NORTH. A FEW TORNADOES MAY
   ALSO OCCUR WITH THE MORE INTENSE SUPERCELLS AS THE LOW-LEVEL JET
   STRENGTHENS EARLY SUNDAY EVENING. WIND DAMAGE WILL BE POSSIBLE WITH
   SUPERCELLS AND BOWING LINE-SEGMENTS ESPECIALLY IF AN MCS CAN
   ORGANIZE DURING THE EARLY EVENING.

 

 

 

 

 

More on EF4 Tornado in Granbury, TX

 

 

On Wednesday evening, there was 16 confirmed tornadoes across northern Texas, one of which was rated an EF4 in Granbury, TX. The image below from the National Weather Service out of Ft. Worth, TX (Courtesy Texas State Police) shows the aerial view of the damage. If you look close, you can actually see some of the homes completely wiped off of their foundation.

 

 

 

 

…NWS DAMAGE SURVEYS FOR 05/15/2013 TORNADO EVENT… …16 TORNADOES HAVE NOW BEEN CONFIRMED. ALL SURVEY CREWS HAVE
RETURNED FOR THE DAY AND SOME OF THEIR INFORMATION HAS BEEN
INCLUDED IN THIS UPDATE…
SO FAR 16 TORNADOES HAVE BEEN CONFIRMED. THE FIRST TORNADO
OCCURRED IN MONTAGUE COUNTY AT 538 PM CDT. THE LAST REPORTED
TORNADO WAS AROUND 1210 AM IN ENNIS.
THIS INFORMATION IS CONSIDERED PRELIMINARY. SURVEY TEAMS WERE
SENT TO JOHNSON COUNTY…HOOD COUNTY…PARKER COUNTY…ELLIS
COUNTY AND MONTAGUE COUNTY. OVER THE NEXT FEW DAYS WE WILL
CONTINUE TO COLLECT DATA…TALK WITH EMERGENCY OFFICIALS AND
RESPONDERS…AND EYE WITNESSES…REVIEW RADAR DATA…PICTURES AND
VIDEOS. THE INFORMATION CONTAINED IN THIS REPORT IS SUBJECT TO AND
LIKELY WILL CHANGE.
========================================
.TORNADO #5 – GRANBURY/HOOD COUNTY…
RATING: EF-4
PATH LENGTH /STATUTE/: 2.75 MILES
PATH WIDTH /MAXIMUM/: 880 YARDS/0.5 MILES
FATALITIES: 6
INJURIES: DOZENS
SIGNIFICANT DAMAGE OCCURRED WITH THIS TORNADO INCLUDING HOMES WIPED
CLEAR OFF THE FOUNDATION. TWO HOMES SUFFERED EF-4 MAGNITUDE DAMAGE
AND SEVERAL MORE SUFFERED EF-3 MAGNITUDE DAMAGE. ADDITIONAL
INFORMATION ON THIS TORNADO WILL BE PROVIDED LATER.

 

 

 

 

 

Raw Video of Damage From EF4 Granbury, TX Tornado

 

 

Here’s some aerial damage video over Grandbury, TX.

 

 

Forecasters say the tornado that claimed six lives and destroyed dozens of homes in North Texas is believed to have had winds up to 200 mph. (May 16)”

 

 

 

 

Wind Map (Bookmark Worthy)
This is a bookmark worthy website for you if you’re interested. I tend to pull this map anytime there are storm system rolling through the country. It does a pretty good with surface features; i.e. fronts/highs/lows/etc. Note the counterclockwise rotation in the wind field across the High Plains. This is the developing low pressure system that will create strong to severe weather potential across the middle part of the country over the next few days.
See the animating website HERE:

 

Thanks for checking in, have a great weekend.
Don’t forget to follow me on Twitter @TNelsonWNTV

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