April 28-30th Severe Threat and Flood event potential

[NavarreDon]

1.63" in the last hour!

[AJF0602]

that is some boundary across NC,.. low 50's to the north, and we are currently 72 with a dewpoint of 72.

[downeastnc]

Jon I am suppose to work 7 to 7 but I might be taking the afternoon off based on the overnight from RAH looking like we might get a big day some of these parameters are sick

 

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
 

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AS OF 340 AM TUESDAY... WEDNESDAY AND WEDNESDAY NIGHT....THE APPROACH OF A STRONGER S/W ROUNDING THE BASE OF THE UPPER TROUGH TO OUR WEST WILL LIKELY TRIGGER ANOTHER ROUND OF STRONG TO SEVERE STORMS WEDNESDAY AFTERNOON- EVENING. THIS S/W APPEARS STRONGER COMPARED TO TODAY`S AND THIS IS REFLECTED IN THE LOW LEVEL JET INCREASING TO AROUND 50KTS BY LATE IN THE AFTERNOON. IN ADDITION...APPEARS THAT THE ATMOSPHERE WILL HAVE A CHANCE TO DESTABILIZE ONCE OVERNIGHT CONVECTION PETERS OUT. MODEL GUIDANCE SUGGEST SBCAPE VALUES SOLIDLY BETWEEN 2500-3500 J/KG AND MLCAPE IN THE IMPRESSIVE 1500-2200 J/KG RANGE. PRESENCE OF LOW LEVEL JET RESULTS IN NICELY CURVED HODOGRAPHS IN THE 0-3KM LAYER WITH LOW LEVEL HELICITY 240-320 M2/S2. THUS...APPEARS TO BE A GREATER THREAT FOR TORNADOES WEDNESDAY AFTERNOON-EVENING AREAWIDE ALONG WITH LARGE HAIL AND DAMAGING WINDS. SEVERE WEATHER THREAT WILL DIMINISH LATE WEDNESDAY EVENING INTO THE OVERNIGHT HOURS AS THE LOW LEVEL JET LIFTS NWD. HOWEVER WILL STILL SEE SCATTERED TO NUMEROUS SHOWERS AND A FEW STORMS OCCUR WELL INTO THE NIGHT...ESPECIALLY EAST OF HIGHWAY 1 AFTER 06Z THURSDAY.

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[Solak]

SPECIAL WEATHER STATEMENT

NATIONAL WEATHER SERVICE RALEIGH NC

549 AM EDT TUE APR 29 2014

...SEVERE THUNDERSTORMS WITH A FEW TORNADOES HIGHLY PROBABLE

ACROSS CENTRAL NORTH CAROLINA TODAY THROUGH WEDNESDAY NIGHT...

SEVERAL BANDS OF SHOWERS AND THUNDERSTORMS WILL CROSS CENTRAL

NORTH CAROLINA TODAY THROUGH WEDNESDAY NIGHT. WHILE THE NEAR

SURFACE AIR MASS IS STABLE EARLY THIS MORNING...THE ATMOSPHERE IS

EXPECTED TO BECOME UNSTABLE...ESPECIALLY ACROSS THE SOUTH AND EAST

SECTIONS OF CENTRAL NORTH CAROLINA THIS AFTERNOON...AND ACROSS

THE ENTIRE AREA TONIGHT THROUGH WEDNESDAY NIGHT.

IN ADDITION...THE WIND PROFILE OVER OUR REGION WILL BE FAVORABLE

FOR THE DEVELOPMENT OF THUNDERSTORMS THAT CONTAIN ROTATING

UPDRAFTS. THESE STORMS WILL HAVE A GREATER POTENTIAL OF PRODUCING

SEVERE WEATHER INCLUDING TORNADOES.

LAW ENFORCEMENT AGENCIES....EMERGENCY MANAGEMENT OFFICIALS... AND

SPOTTER GROUPS SHOULD MONITOR THE LATEST WEATHER CONDITIONS AND BE

PREPARED FOR POSSIBLE ACTIONS AND AUGMENT STAFFING THIS AFTERNOON

THROUGH WEDNESDAY NIGHT.

PEOPLE ACROSS CENTRAL NORTH CAROLINA NEED TO KEEP ABREAST OF THE

LATEST WEATHER INFORMATION TODAY THROUGH WEDNESDAY NIGHT. HAVE A

SOURCE OF WEATHER INFORMATION READILY AVAILABLE. ALSO...MAKE

CONTINGENT PLANS NOW OF WHERE YOU WOULD GO TO TAKE SHELTER IN THE

EVENT OF WEATHER EMERGENCY WHETHER YOU ARE AT HOME...WORK...OR IN

YOUR CAR.

[NavarreDon]

Getting close to 3" so far. Just a long night with the storms. In my area the have been about 30 water rescues. A mudslide, & a road washed away by a sinkhole. Will update shortly with links.

Edit: we just lost our power as the rain stopped!

[Solak]

[Hvward]

Wow guys great OBS while I was sleeping!  Today is a nervous day for a lot of us.  It will be interesting to see if any of those mountain tornado warnings verified.  I bet those aren't the last that we will see with this storm!

[Cold Rain]

Cool and drizzly out this morning. Doesn't fell like a severe weather day at all.

[NavarreDon]

Just got power restored, outage due to trees on lines. Wind has really started whipping. Not sure how much of that the saturated ground will take. Here are some radar shots from last night.

 

 

[UpstateSCBud]

Upstate SC has really missed out on any action so far. With it already being so cloudy and the light rain this morning, I don't see a severe threat panning out for us today here.

[NavarreDon]

Link to WLOS story on flooding in Woodfin, NC (between Weaverville & Asheville)

 

http://www.wlos.com/shared/news/features/top-stories/stories/wlos_flooding-forces-evacuations-16026.shtml

 

Link to WYFF pictures in Woodfin.

 

http://www.wyff4.com/news/pictures-water-rescue-flooding/25711386?utm_source=hootsuite&utm_medium=twitter&utm_campaign=wyffnews4&utm_source=hootsuite&utm_medium=facebook&utm_campaign=wyff%2Bnews%2B4

[AJF0602]

looking at the visibile imagery, eastern NC and far east SC should see some decent heating today with a thin cloud layer.

[Hvward]

Upstate SC has really missed out on any action so far. With it already being so cloudy and the light rain this morning, I don't see a severe threat panning out for us today here.

 

Upstate SC has pretty decent severe indicators.  This is not a day to put your guard down, these storms mean business.

[calculus1]

Stuck in the wedge here in the NW NC piedmont.  I'm beginning to doubt the originally forecasted copious rainfall amounts for my area.  The mountains and foothills received 1-2 inches of rainfall overnight just 20+ miles west of me.  Unless this wedge erodes pretty quickly, I think Hickory is going to be the relative minimum area for precipitation totals for this entire event.  The mountains should get a lot of rainfall and further to the east should also cash in.  There's going to be rain in my backyard, but I don't see the original 3+ inch totals materializing anymore.  I really hope that I'm wrong, but that's my current take on the situation.

 

Radar estimated rainfall totals over the past 12 hours:

 

[Poimen]

Look out as that wedge boundary pulls north today, areas along and near that boundary will probably be the focus for tornadic thunderstorms this afternoon.

[NavarreDon]

Calc. GSP update below.....I can tell you that at least for mby those radar estimates are light. I am at 2.85" now.

 

.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 AM...SHOWER BAND IS BECOMING INCREASINGLY RAGGED ACROSS
THE HEART OF THE CWA EARLY THIS MORNING...AND THIS TREND IS LIKELY
TO CONTINUE...SO A LULL IN PRECIP APPEARS ON TAP FOR MUCH OF THE
AREA LATER THIS MORNING. HOWEVER...THE ATM WILL DESTABILIZE SOUTH OF
WEDGE FRONT LATER THIS MORNING INTO THE AFTERNOON...AND ADDITIONAL
SCATTERED TO NUMEROUS SHOWERS AND TS SHOULD REDEVELOP.

BAND OF WIDESPREAD SHOWERS WITH CLUSTERS OF EMBEDDED THUNDERSTORMS
WILL CONTINUE TO OOZE EAST ACROSS THE NORTHWEST HALF OF THE FORECAST
AREA THROUGH THE MORNING. THE MOST ROBUST CONVECTION WAS PUSHING
INTO THE FOOTHILLS...AND WILL BECOME LESS ROOTED IN THE BOUNDARY
LAYER...AS IT LIFTS INTO THE SHALLOW COOL AIR MASS NORTH OF WEDGE
FRONT. ALTHOUGH ISOLATED LARGE HAIL WILL STILL BE A CONCERN...THE
TORNADO THREAT WILL DIMINISH WITH THIS ACTIVITY AS IT BECOMES
ELEVATED. HOWEVER...ROBUST DEEP CONVECTION CONTINUES TO APPROACH THE
AREA FROM NORTH GEORGIA...WHILE ADDITIONAL DEEP CONVECTION COULD
DEVELOP DUE TO SW UPSLOPE FLOW...SO THE TORNADO THREAT...WHILE SMALL
IS BY NO MEANS ZERO. OTHERWISE...ALTHOUGH THE LARGE SCALE CONVECTIVE
BAND MAY BECOME INCREASINGLY DISORGANIZED AND LESS INTENSE AS IT
SHIFTS EAST THIS MORNING...POPS WILL INCREASE GRADUALLY FROM WEST TO
EAST ACROSS THE PIEDMONT...WITH MOST AREAS SEEING A CATEGORICAL POP
BY AFTERNOON. BUOYANCY WILL REMAIN ROBUST IN THE WARM SECTOR AHEAD
OF THE ONGOING ACTIVITY...WITH SBCAPE PROGGED TO EXCEED 1500 J/KG
ACROSS SOUTHERN PIEDMONT AREAS THIS AFTERNOON. LOW LEVEL SHEAR WILL
REMAIN IN THE 30-40 KTS RANGE...AND ISOLATED TORNADOES WILL REMAIN
POSSIBLE...ESP IF ANY DISCRETE CELLS DEVELOP IN THE WARM SECTOR AND
APPROACH THE WEDGE FRONT.

SPEAKING OF THE WEDGE FRONT...IT HAS PENETRATED MUCH FARTHER SOUTH
THAN WAS ANTICIPATED ATTM YESTERDAY. WHILE THE SHORT TERM MODELS
PREDICTABLY LIFT THE BOUNDARY NORTH AND BASICALLY OUT OF THE AREA
THROUGH THE DAY...I DON/T HAVE A LOT OF FAITH IN THAT. MAX TEMPS
HAVE BEEN LOWERED QUITE A BIT ACROSS THE NC PIEDMONT...TO THE MID
60S ACROSS THE EXTREME NORTH...AND MID/UPPER 70S ACROSS THE
SOUTH.

ANOTHER ROUND OF INTENSE CONVECTION WILL DEVELOP IN THE UNSTABLE/
HIGHLY SHEARED ENVIRONMENT OVER THE TENN VALLEY LATER TODAY...LIKELY
ORGANIZING INTO ANOTHER LARGE SCALE BAND THAT WILL APPROACH THE AREA
THIS EVENING...SUPPORTING A CONTINUATION OF CATEGORICAL POPS...AND
ALSO EXTENDING THE SEVERE WEATHER THREAT THROUGH TONIGHT. FLASH
FLOODING WILL ALSO BECOME INCREASINGLY LIKELY LATER TODAY INTO
TONIGHT...AS AREAS WORKED OVER THIS MORNING RECEIVE ADDITIONAL HEAVY
RAINFALL IN CONVECTION TONIGHT.

[Brick Tamland]

Cool and drizzly out this morning. Doesn't fell like a severe weather day at all.

 

 

I was thinking the same thing. I'm hoping the clouds stick around today and keep the instability down in the Triangle. It looks like RAH thinks the front will drift north and Raleigh will be right on the line, though. Maybe we can dodge a bullet here today, but it's going to be hard to dodge it today and tomorrow, too.

[calculus1]

Calc. GSP update below.....I can tell you that at least for mby those radar estimates are light. I am at 2.85" now.

SPEAKING OF THE WEDGE FRONT...IT HAS PENETRATED MUCH FARTHER SOUTH

THAN WAS ANTICIPATED ATTM YESTERDAY. WHILE THE SHORT TERM MODELS

PREDICTABLY LIFT THE BOUNDARY NORTH AND BASICALLY OUT OF THE AREA

THROUGH THE DAY...I DON/T HAVE A LOT OF FAITH IN THAT. MAX TEMPS

HAVE BEEN LOWERED QUITE A BIT ACROSS THE NC PIEDMONT...TO THE MID

60S ACROSS THE EXTREME NORTH...AND MID/UPPER 70S ACROSS THE

SOUTH.

 

I know those estimates usually are underdone, but that's an incredible total for you already, Don.  Wowza!  You could easily push 6 inches of rainfall when this system finally winds down.

 

So, it appears my thinking was inline with GSP too.  The wedge is strong with this one...

[Cold Rain]

I was thinking the same thing. I'm hoping the clouds stick around today and keep the instability down in the Triangle. It looks like RAH thinks the front will drift north and Raleigh will be right on the line, though. Maybe we can dodge a bullet here today, but it's going to be hard to dodge it today and tomorrow, too.

 

We may dodge it today.  It seems like wedging hangs on longer than forecast, usually.  It's going to be hard for the wedge to retreat today.  It might very well do it, but it's locked in pretty good.  The temp is 53 at RDU (as of 8:00) and 61 in Lumberton (as of 8:00).  That's a fairly small spread for such a distance.  I was hoping to see a bigger contrast.  We'll see.

 

But if the boundary does indeed set up just north of Raleigh, that would put the area at a greater risk for rotating storms.

[Brick Tamland]

We may dodge it today.  It seems like wedging hangs on longer than forecast, usually.  It's going to be hard for the wedge to retreat today.  It might very well do it, but it's locked in pretty good.  The temp is 53 at RDU (as of 8:00) and 61 in Lumberton (as of 8:00).  That's a fairly small spread for such a distance.  I was hoping to see a bigger contrast.  We'll see.

 

But if the boundary does indeed set up just north of Raleigh, that would put the area at a greater risk for rotating storms.

 

Yes, that is what I was afraid of, and the graphic from RAH this morning shows just that.

[Poimen]

From the SPC morning update for day 1:

...CAROLINAS THIS AFTERNOON INTO TONIGHT...   A BELT OF 25-30 KT SLY FLOW AT 850 MB WILL BE MAINTAINED TODAY E OF   THE CNTRL/SRN APPALACHIANS WHICH WILL PROMOTE THE POLEWARD FLUX OF   65-70 F BOUNDARY-LAYER DEWPOINTS THROUGH THE WARM SECTOR. AND WHILE   MIDLEVEL LAPSE RATES WILL NOT BE PARTICULARLY STEEP...THE INCREASING   MOISTURE COUPLED WITH DAYTIME HEATING WILL YIELD AFTERNOON MLCAPE OF   1000-1500 J/KG.   LOW-LEVEL CONVERGENCE/UPLIFT ALONG THE NWD-MOVING WEDGE FRONT AND/OR   RESIDUAL CONVECTIVE OUTFLOW BOUNDARIES ASSOCIATED WITH A DECAYING   MCS MOVING INTO THE AREA FROM THE SW IS EXPECTED TO FOSTER ISOLATED   TO SCATTERED TSTMS BY AFTERNOON WITHIN A KINEMATIC ENVIRONMENT   FEATURING A VERTICALLY VEERING WIND PROFILE WITH 30-40 KT OF   DEEP-LAYER SHEAR. ORGANIZED STORM MODES INCLUDING SUPERCELLS ARE   POSSIBLE WITH THE PRIMARY HAZARDS BEING LARGE HAIL AND DAMAGING   WINDS. THE GREATEST TORNADO THREAT MAY MATERIALIZE ACROSS CNTRL NC   THIS AFTERNOON INVOF OF THE WEDGE FRONT WHERE LOW-LEVEL SHEAR IS   ENHANCED.

[Brick Tamland]

[downeastnc]

 

From the SPC morning update for day 1:

...CAROLINAS THIS AFTERNOON INTO TONIGHT...   A BELT OF 25-30 KT SLY FLOW AT 850 MB WILL BE MAINTAINED TODAY E OF   THE CNTRL/SRN APPALACHIANS WHICH WILL PROMOTE THE POLEWARD FLUX OF   65-70 F BOUNDARY-LAYER DEWPOINTS THROUGH THE WARM SECTOR. AND WHILE   MIDLEVEL LAPSE RATES WILL NOT BE PARTICULARLY STEEP...THE INCREASING   MOISTURE COUPLED WITH DAYTIME HEATING WILL YIELD AFTERNOON MLCAPE OF   1000-1500 J/KG.   LOW-LEVEL CONVERGENCE/UPLIFT ALONG THE NWD-MOVING WEDGE FRONT AND/OR   RESIDUAL CONVECTIVE OUTFLOW BOUNDARIES ASSOCIATED WITH A DECAYING   MCS MOVING INTO THE AREA FROM THE SW IS EXPECTED TO FOSTER ISOLATED   TO SCATTERED TSTMS BY AFTERNOON WITHIN A KINEMATIC ENVIRONMENT   FEATURING A VERTICALLY VEERING WIND PROFILE WITH 30-40 KT OF   DEEP-LAYER SHEAR. ORGANIZED STORM MODES INCLUDING SUPERCELLS ARE   POSSIBLE WITH THE PRIMARY HAZARDS BEING LARGE HAIL AND DAMAGING   WINDS. THE GREATEST TORNADO THREAT MAY MATERIALIZE ACROSS CNTRL NC   THIS AFTERNOON INVOF OF THE WEDGE FRONT WHERE LOW-LEVEL SHEAR IS   ENHANCED.

 

Yeah hopefully anything that does spin up today will be weaker and short lived, if that front gets north early enough it could be a rough afternoon in and around the triangle , I am taking a half day off tomorrow so me and Shaggy can chase and I know Bozart is also going to chase its is shaping up to be the best ( or worst depending on view) setup for widespread tornados since April 2011. Also gotta hate for AL and Miss the same areas that got raked yesterday look to get it again today......

[Amos83]

socked in with fog currently... I'm hoping the wedge front can get its act together and move north enough to give us some sun today. I don't want to see any tornados but I want to see some big boomers.

 

Stay safe today and tomorrow everyone!

[Solak]

Wind map shows the surface wedge/boundary pretty well

 

http://hint.fm/wind/

[mackerel_sky]

Currently 69/66 - juicy outside and sun breaking out. Could be a rough afternoon!

[Cold Rain]

Upgraded to a mod risk of strong to severe wedging holding on longer than expected this afternoon.  Under a severe fog warning in downtown Raleigh right now.  High drizzle, large overcast, and strong/long-track fog probable throughout the day.

[downeastnc]

Upgraded to a mod risk of strong to severe wedging holding on longer than expected this afternoon.  Under a severe fog warning in downtown Raleigh right now.  High drizzle, large overcast, and strong/long-track fog probable throughout the day.

 

Suns trying to burn through here but the models always erode wedges to fast.....finally cracked 60 here

[Cold Rain]

Suns trying to burn through here but the models always erode wedges to fast.....finally cracked 60 here

 

Yeah...just posted some Obs...looks like we're finally beginning to see some progress with the boundary now.  Once it goes by, instability should quickly rise, especially if we get any real sunshine.

[Poimen]

Yeah..visible imagery shows the low cloud deck eroding SE of the Triangle from SE to NW. Will be interesting to see if we can break out of this low cloud deck in the Triangle by early afternoon.