***April Severe Weather Thread***

I still don't get it, and I'm not alone, as several pros are failing to grasp how the NWS is justifying this level of threatening weather with the necessary products for this to happen are so out of phase.

However, they say it's going to happen so I'm going to make sure you are aware of it.

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT WED MAR 30 2016

VALID 311200Z - 011200Z

...THERE IS AN ENH RISK OF SVR TSTMS ACROSS PORTIONS MUCH OF
MS...FAR NE LA/SE AR...W TN/KY...SE IL AND SW IND...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE DEEP SOUTH TO LAKE
MICHIGAN...

...THERE IS A MRGL RISK OF SVR TSTMS FROM THE NORTHERN GULF COAST TO
THE MIDWEST AND PORTIONS OF THE CAROLINAS...

...SUMMARY...
MULTIPLE ROUNDS OF SEVERE THUNDERSTORMS ARE EXPECTED FROM THE LOWER
MISSISSIPPI VALLEY NORTH AND EAST TO THE MIDDLE MISSISSIPPI AND OHIO
VALLEYS INTO THE DEEP SOUTH ON THURSDAY. TORNADOES...VERY LARGE HAIL
AND DAMAGING WINDS ALL WILL BE POSSIBLE.

...SYNOPSIS...

MULTIFACETED THREAT WILL UNFOLD ON THURSDAY. STRONG VERTICAL SHEAR
ASSOCIATED WITH LARGER-SCALE UPPER TROUGH WILL COINCIDE WITH
EXPANDING WARM SECTOR FROM THE GULF COAST TO THE MID-MS/OH VALLEY
REGION. SPORADIC SEVERE WILL LIKELY BE ONGOING DURING THE MORNING
ACROSS PARTS OF THE LOWER MS VALLEY WITH BROADER AREA OF
SHOWERS/THUNDERSTORMS FROM LOWER MI S/SW TO THE MID/LOWER MS VALLEY.
THIS ACTIVITY SHOULD DIMINISH/SHIFT E/NE TO NEAR OH THROUGH THE
WESTERN TN VALLEY BY 18Z. AS A RESULT...RECOVERY ACROSS THE WARM
SECTOR APPEARS LIKELY. A SECOND ROUND OF SEVERE THUNDERSTORMS SHOULD
THEN EVOLVE ALONG THE SOUTHEASTWARD ADVANCING COLD FRONT DURING THE
LATE AFTERNOON INTO THE OVERNIGHT HOURS FROM NEAR LAKE MICHIGAN
SOUTHWARD THROUGH THE DEEP SOUTH.

...LOWER MS AND TN VALLEYS REGION...

AREAS OF SCATTERED THUNDERSTORM CLUSTERS AND BOWING LINE SEGMENTS
WILL LIKELY BE PRODUCING AT LEAST ISOLATED SEVERE AT THE BEGINNING
OF THE PERIOD. ALL HAZARD TYPES WILL BE POSSIBLE WITH THIS INITIAL
ACTIVITY...THOUGH LARGE HAIL IS THE MAIN CONCERN AS STORMS COULD BE
SLIGHTLY ELEVATED. ANY STORMS THAT ARE SURFACE BASED HOWEVER WILL
HAVE AN ACCOMPANYING STRONG WIND AND TORNADO THREAT. THIS ACTIVITY
SHOULD MIGRATE NORTHEAST AND DIMINISH DURING THE MORNING...WHILE
LEAVING AN OUTFLOW BOUNDARY AND COLD POOL ACROSS PARTS OF THE
ARKLAMISS REGION. STRONG WARM ADVECTION REGIME AND AT LEAST MODEST
SURFACE HEATING SHOULD ALLOW FOR AIRMASS RECOVERY BY THE
AFTERNOON...THOUGH THERE COULD BE POCKETS WHERE RECOVERY IS POOR IN
A RELATIVE SENSE...LEADING TO GAPS IN HIGHER PROBABILITY SEVERE.
UNCERTAINTY IN WHERE THIS MAY OCCUR WILL NEGATE ANY SEPARATION IN
ENHANCED PROBABILITY AREA. ADDITIONAL UNCERTAINTY EXISTS WITH
REGARDS TO STORM COVERAGE GIVEN STRONGER FORCING FOR ASCENT WILL BE
FOCUSED MORE OVER THE MID-MS/OH VALLEY REGION.

MID TO UPPER 60S DEWPOINTS COUPLED WITH MODERATE INSTABILITY...STEEP
LAPSE RATES AND STRONG LOW TO MID-LEVEL SHEAR WILL SUPPORT
SUPERCELLS CAPABLE OF TORNADOES...LARGE HAIL AND DAMAGING WINDS.
GIVEN THERMODYNAMIC AND KINEMATIC PARAMETER SPACE...SIG SEVERE
POTENTIAL EXISTS WITH VERY LARGE HAIL AND PERHAPS A STRONG TORNADO
OR TWO POSSIBLE. DURING THE NIGHT AS A SWLY LLJ INCREASES...STORMS
MAY CONCEAL INTO AN EASTWARD PROPAGATING BOW/MCS...IMPACTING
PORTIONS OF AL...MIDDLE/WRN TN AND INTO GA.

...MID-MS AND LOWER OH VALLEY REGION...

ONGOING CONVECTION AT THE BEGINNING OF THE PERIOD WILL SHIFT
NORTHEAST TOWARD THE MID/UPPER OH VALLEY AND APPALACHIANS BY MIDDAY.
GIVEN STRONG SOUTH/SOUTHWESTERLY DEEP LAYER FLOW...MOISTURE WILL
QUICKLY STREAM NORTHWARD AND HEATING IN THE WAKE OF MORNING
CONVECTION WILL RESULT IN STRONG DESTABILIZATION WITH SBCAPE VALUES
APPROACHING 1000 J/KG AS FAR NORTH AND NORTHERN IL/IND INTO FAR SW
LOWER MI. FURTHER SOUTH ACROSS PARTS OF SOUTHERN IL...AND ADJACENT
PORTIONS OF THE LOWER OH VALLEY...BETTER MOISTURE WILL RESULT IN
HIGHER CAPE VALUES...APPROACHING 2500 J/KG. THUNDERSTORMS ARE
EXPECTED TO DEVELOP ALONG THE SOUTHEASTWARD ADVANCING COLD FRONT
NEAR THE SFC LOW OVER NRN INTO CNTRL IL BY MID-AFTERNOON AND
INCREASE IN COVERAGE/INTENSITY WITH SOUTHERN AND EASTERN EXTENT INTO
PARTS OF SE IL/SW IND/W KY/FAR SE MO. SUPERCELLS WITH ALL SEVERE
HAZARDS WILL BE POSSIBLE ACROSS THE SLIGHT RISK AREA WITH LARGE HAIL
BEING THE PRIMARY CONCERN. ACROSS THE ENHANCED RISK AREA...SIG HAIL
AND A FEW TORNADOES /POTENTIALLY STRONG/ ARE POSSIBLE. THIS ACTIVITY
SHOULD GROW UPSCALE INTO BOWING SEGMENTS WITH EASTWARD EXTENT
OVERNIGHT FROM CENTRAL IND/KY INTO OH AND THE APPALACHIANS BY THE
END OF THE PERIOD.

..LEITMAN.. 03/30/2016

James Spann's pm weather video.

From the Weather Junkies page this morning.

Good Morning Weather Junkies.

Things got serious overnight to our west and instead of a bunch of prognosticating, I'm simply going to give you the SPC's outlook for today valid until 1200z (8pm est, 7pm cst) and the day two outlook, plus their synopsis.

Weather Radios are your friend today from MS to GA and points north and south.

Stay Safe!!!

SPC AC 310602

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0102 AM CDT THU MAR 31 2016

VALID 311200Z - 011200Z

...THERE IS AN ENH RISK OF SVR TSTMS ACROSS MUCH OF NRN MS AND
AL...TN...SWRN KY...FAR ERN AR AND NERN LA...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GULF COAST NWD
ACROSS THE OH VALLEY...

...THERE IS A MRGL RISK OF SVR TSTMS FROM LOWER MI SWD TO THE GULF
OF MEXICO...

...SUMMARY...
SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS A LARGE AREA EXTENDING FROM
THE CENTRAL GULF COAST STATES NORTHWARD ACROSS THE OHIO VALLEY TO
SOUTHERN MICHIGAN. THE GREATEST THREAT OF TORNADOES AND VERY LARGE
HAIL WILL BE CENTERED OVER NORTHERN MISSISSIPPI AND ALABAMA INTO
TENNESSEE AND SOUTHERN KENTUCKY. MORE ISOLATED SEVERE STORMS ARE
POSSIBLE DURING THE EVENING INTO THE WESTERN CAROLINAS...AND FRIDAY
MORNING ALONG THE CENTRAL GULF COAST.

...SYNOPSIS...
A BROAD BELT OF SWLY FLOW ALOFT WILL STRETCH FROM NRN MEXICO ACROSS
MUCH OF THE ERN STATES WITH LEADING SHORTWAVE TROUGH AND ASSOCIATED
100 KT MIDLEVEL SPEED MAX MOVING FROM THE MID MS VALLEY INTO THE
GREAT LAKES. A SECONDARY UPPER LEVEL JET WILL ALSO BE PRESENT
FARTHER S FROM TX ACROSS THE CNTRL GULF COAST. AT THE SURFACE...LOW
PRESSURE WILL MOVE FROM NRN IL INTO LOWER MI WITH A STALLING FRONT
EXTENDING SWWD ACROSS IL AND INTO ERN TX BY LATE AFTERNOON.

AHEAD OF THIS FRONT...STRONG SLY LOW-LEVEL FLOW WILL MAINTAIN A NWD
FLUX OF MOISTURE WITH 60 F DEWPOINTS TO THE OH RIVER...AND MID TO
UPPER 60S F TO THE S. THE COMBINATION OF A VERY MOIST AND UNSTABLE
AIR MASS WITH COOL TEMPERATURES ALOFT...ALONG WITH AMPLE DEEP-LAYER
SHEAR WILL BE PRESENT OVER A LARGE AREA AND WILL SUPPORT SEVERE
STORMS. HOWEVER...THE FORECAST IS RELATIVELY COMPLEX OWING TO EARLY
DAY RAIN AND STORMS...AS WELL AS SUBTLE FORCING FOR ASCENT
ESPECIALLY ACROSS SRN AREAS. THAT SAID...A CONDITIONAL THREAT OF
VERY LARGE HAIL AND PERHAPS A COUPLE STRONG TORNADOES DOES EXIST
DURING THE AFTERNOON AND EVENING OVER THE ENHANCED RISK AREA...WITH
MORE OF AN ISOLATED RISK PERIPHERALLY.

...SRN AND ERN IL...IND...KY...
A BROKEN LINE OF STORMS IS EXPECTED TO FORM RELATIVELY EARLY IN THE
DAY...BY AROUND 18Z...FROM THE SFC LOW IN NRN IL SWD TO THE OH
RIVER. WIND FIELDS WILL BE EXTREMELY STRONG WITH OVER 50 KTS AT 700
MB. ONLY MARGINAL LOW-LEVEL SRH VALUES ARE EXPECTED TO BE PRESENT
OWING TO VEERING WINDS WITH TIME...HOWEVER...LOW-LEVEL BUOYANCY
SHOULD BE SUFFICIENT FOR SCATTERED SEVERE STORMS WITH LONG
HODOGRAPHS SUPPORTING HAIL. AN ISOLATED TORNADO CANNOT BE RULED OUT
GIVEN FAVORABLE CELLULAR STORM MODE AS WELL...BUT FAST-MOVING
SPLITTING CELLS SEEM PROBABLE. A FEW DAMAGING WIND GUSTS ARE ALSO
EXPECTED GIVEN VERY FAST STORM MOTIONS AND OUTFLOW.

...ERN AR/NRN LA EWD ACROSS TN...CNTRL AND NRN MS/AL...SRN
APPALACHIANS...
A COMPLICATED FORECAST SCENARIO WILL UNFOLD TODAY...BEGINNING WITH A
BATCH OF RAIN AND STORMS EARLY IN THE MORNING ACROSS MUCH OF NRN MS
AND WRN AL. THIS ACTIVITY IS EXPECTED TO SHIFT EWD DURING THE DAY
OVER AL AND NRN GA....SUPPORTED BY DIURNAL DESTABILIZATION AND A
STRONG SWLY LOW-LEVEL JET. THUS...SOME OF THIS ACTIVITY MAY BECOME
SEVERE WITH DAMAGING WINDS AND/OR AN ISOLATED TORNADO THREAT.

IN THE WAKE OF THIS ACTIVITY...STRONG HEATING WILL OCCUR OVER THE
MID TO LOWER MS VALLEY REGION. THE COLD FRONT WILL BECOME NEARLY
STATIONARY...ALLOWING FOR FULL HEATING AND A DEEPENING MOIST
BOUNDARY LAYER WHICH WILL LEAD TO AREAS OF STRONG INSTABILITY AND
LITTLE INHIBITION. FORECAST SOUNDINGS INDICATE AN ELEVATED MIXED
LAYER WITH 7.5 TO 8.0 C/KM 700-500 MB LAPSE RATES. COUPLED WITH A
VEERING WIND PROFILE WITH HEIGHT...THIS SHOULD SET THE STAGE FOR
ROBUST SUPERCELL POTENTIAL INCLUDING VERY LARGE DAMAGING HAIL AND
TORNADOES. STORM INITIATION WILL LIKELY BE ALONG THE FRONT IN THE
18-20Z TIME FRAME FROM WRN TN/ERN AR INTO THE SABINE RIVER
VALLEY...WITH STORMS DEVELOPING ENEWD WITH TIME. OF SPECIAL INTEREST
IS ANY OUTFLOW BOUNDARY FROM EARLY DAY STORMS. SUCH AN AREA WOULD
LIKELY HARBOR ENHANCED LOW-LEVEL SHEAR AND MAY SUPPORT STRONG
TORNADOES BY LATE AFTERNOON AND INTO THE EVENING WITH THE AREA OF
GREATEST CONCERN INCLUDING NRN MS...NRN AL...AND SRN TN.

..JEWELL/ROGERS.. 03/31/2016

Looks like our next shot at a little bumpy weather might be on Tuesday. Daytime heating will contribute to good dewpoints and convective lift to toss things around a bit.

Here's a couple of gifs for you to view to get an idea (Lifted index / helicity values, and supercell composite index) of what's to come.

Timing? At present we are looking at around 10am til about midnight from west to SE Coast as it progresses across the state.
Areas effected? The entire western line of the state at first, then SOWEGA and from the I-20 corridor down through middle and SE Ga as the system moves through. The NWS convective outlook hasn't caught up with the model potential yet, so give them a day and then I'll update what they're saying about our potential.

Well, according to the hi res nam the supercell potential will barely make it into Alabama before dying down, and then slightly reform over south alabama and georgia before getting out of here.



However it would seem that the hi res nam sim reflectivity would suggest otherwise. Rain should start moving in later this afternoon/evening and last on and off through to tomorrow night.

This afternoons HRRR simref radar projection looks like S MS and S AL will get the worst of the storm cells but there is always the potential for hit and miss strong cells in with our weather as well.

Go to this link and check it out.

http://www.pivotalweather.com/model.php?m=hrrr&p=refcmp&rh=2016041118&fh=loop&r=us_se&dpdt=

Kind of a look ahead, and now that the GFS is on board with that whacky CFSv2, we can expect some good rain around May 3rd / 4th. Nothing really severe showing at this time for that period, but it bears watching as we get closer.

Here's a 24hr qpf (rainfall) map to give a clue what we might could expect.