Thursday, May 6, 2010

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 060539
SWODY1
SPC AC 060537

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1237 AM CDT THU MAY 06 2010

VALID 061200Z - 071200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL
PLAINS AND MID MS VALLEY...

...CENTRAL PLAINS/MID MS VALLEY...

SFC CYCLONE IS EXPECTED TO REORGANIZE IN THE LEE OF THE COLORADO
ROCKIES LATER TODAY AS STRONG UVV OVERSPREADS THE CNTRL HIGH PLAINS
IN ADVANCE OF SHORTWAVE TROUGH. IN RESPONSE TO THIS EVOLUTION...ELY
BOUNDARY LAYER FLOW WILL DEEPEN ACROSS NERN CO/SWRN NEB/NWRN KS
ENSURING THE CONTINUED MOISTENING OF LOW LEVEL AIRMASS. LATEST
MODEL GUIDANCE STRONGLY SUGGESTS THUNDERSTORMS WILL INITIATE OVER
THE UPSLOPE REGIONS OF THE CNTRL HIGH PLAINS...JUST NORTH OF THE SFC
LOW CENTER BY MID-LATE AFTERNOON. THIS ACTIVITY WILL BE STRONGLY
SHEARED...BUT INSTABILITY-STARVED WITHIN FAVORABLY DIFFLUENT HIGH
LEVEL FLOW REGIME.

LATEST DIAGNOSTIC DATA...REGARDING MOISTURE RECOVERY OVER
TX...SUGGESTS MARITIME AIRMASS WILL BE SLOW TO RETURN ACROSS OK INTO
KS PRIOR TO AFTERNOON CONVECTIVE INITIATION OVER THE HIGH PLAINS.
IT APPEARS SFC DEW POINTS WILL GRADUALLY INCREASE ALONG THE I-70
CORRIDOR...COINCIDENT WITH SHARPENING WARM FRONT. THIS SHOULD
ENCOURAGE AN UPWARD EVOLVING MCS ALONG/NORTH OF FRONTAL ZONE DURING
THE EVENING/OVERNIGHT HOURS AS LLJ INCREASES AND VEERS ACROSS ERN
KS/MO. 00Z SOUNDINGS ACROSS THE WARM SECTOR SUGGEST SFC-BASED
PARCELS WILL REMAIN CAPPED EAST OF THE HIGH PLAINS...THUS AN
ELEVATED CLUSTER OF STORMS SHOULD PROPAGATE ACROSS MUCH OF NRN
KS/SRN NEB INTO THE MID MS VALLEY AFTER DARK. LARGE HAIL IS THE
GREATEST SEVERE RISK..AND PERHAPS DAMAGING WINDS NEAR THE FRONTAL
ZONE.

...NERN U.S...

STRONG SHORTWAVE TROUGH WILL BEGIN TO INFLUENCE MUCH OF THE NERN
U.S. EARLY IN THE PERIOD AS WLY FLOW DEEPENS BENEATH A STRONG MID
LEVEL JET. A NARROW AXIS OF PRE-FRONTAL MOISTURE OVER PA/UPSTATE NY
SHOULD BE ADVECTED DOWNSTREAM ACROSS MUCH OF NEW ENGLAND ENHANCING
INSTABILITY WITHIN VEERED FLOW AND STEEP LAPSE RATE ENVIRONMENT.
FORECAST SOUNDINGS SUGGEST AIRMASS WILL WARM QUICKLY AND ISOLATED
THUNDERSTORMS MAY DEVELOP WITHIN STRONGLY SHEARED PATTERN. AT THIS
TIME IT DOES NOT APPEAR COVERAGE OF THUNDERSTORM ACTIVITY WILL
WARRANT A SLIGHT RISK...HOWEVER STEEP LAPSE RATES AND STRONGLY
SHEARED AIRMASS DO SEEM TO SUPPORT AT LEAST LOW PROBABILITIES FOR
GUSTY WINDS AND HAIL ACROSS PRE-FRONTAL REGIONS OF THE NERN
U.S....EXTENDING INTO PORTIONS OF THE TIDEWATER REGION OF DE/MD/VA.

...FL...

EARLY MORNING WV IMAGERY DEPICTS A WELL DEFINED MID LEVEL SHORTWAVE
TROUGH OVER THE ERN GULF OF MEXICO...DRIFTING EWD IN LINE WITH
LATEST MODEL GUIDANCE. THIS FEATURE IS NOT EXPECTED TO STRENGTHEN
WIND FIELDS APPRECIABLY...HOWEVER CONVERGENCE SHOULD BE MAXIMIZED
ALONG A FAIRLY WELL DEFINED EAST COAST SEA BREEZE. GIVEN THE
RELATIVELY WEAK WIND FIELDS AND COOL MID LEVEL TEMPERATURES...IT
APPEARS DIURNAL HEATING AND CONVERGENCE WILL CONTRIBUTE GREATLY TO
SCATTERED STRONG THUNDERSTORMS BY MID DAY ACROSS THE CNTRL/SRN
PENINSULA. A FEW STORMS MAY PRODUCE HAIL AND GUSTY WINDS.

..DARROW/JEWELL.. 05/06/2010

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