FXUS63 KOAX 310823
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
323 AM CDT TUE MAY 31 2011
.DISCUSSION...
QUIET AND COOLER WEATHER IS IN STORE FOR TODAY BEHIND THE LINE OF
THUNDERSTORMS. SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES BROAD
UPPER-LEVEL TROUGH IN THE WESTERN US...WITH LOW CENTERS IN NORTHEAST
WY/EASTERN MT AND JUST OFF THE PACIFIC NORTHWEST COAST. UPPER-LEVEL
HIGH WAS CENTERED IN THE APPALACHIANS...WITH STRONG SOUTHWESTERLY
FLOW ACROSS THE CENTRAL PLAINS TO NORTHERN GREAT LAKES. 850MB LOW
WAS CENTERED IN THE WESTERN DAKOTAS...WITH 850MB DEWPOINTS ABOVE 8C
ACROSS MUCH OF THE EASTERN HALF OF THE CONUS...AND WITH AN AXIS OF
16C+ DEWPOINTS FROM CENTRAL TX THROUGH EASTERN NEB INTO NORTHERN
MN. SURFACE LOW AT 07Z WAS CENTERED IN NORTHEAST ND...WITH
SECONDARY LOW IN SOUTH CENTRAL KS/NORTH CENTRAL OK...AND FRONT
EXTENDING BETWEEN.
MAIN FORECAST CONCERN IS RAIN/THUNDER POTENTIAL ON
WEDNESDAY/WEDNESDAY NIGHT. COOLER TEMPERATURES AND CLEARING SKIES
ARE EXPECTED TODAY AND TONIGHT AS HIGH PRESSURE MOVES THROUGH IN
WAKE OF THE LEADING UPPER LOW MOVING FROM THE DAKOTAS INTO THE UPPER
GREAT LAKES. RETURN FLOW AROUND THE BACK SIDE OF THE HIGH WILL DRAW
MOISTURE NORTHWARD INTO THE CENTRAL PLAINS BEGINNING LATE TUESDAY
NIGHT AND MAINLY ON WEDNESDAY AS SURFACE AND MID-LEVEL RIDGE
RETREATS EASTWARD. INCREASING LOW/MID LEVEL MOISTURE WILL
CONTRIBUTE TO DESTABILIZATION ON WEDNESDAY AFTERNOON...ESPECIALLY
IN EASTERN NEBRASKA. SOME QUESTION ABOUT WHETHER CAP WILL BE ABLE
TO BREAK...ESPECIALLY SINCE FORCING ON WEDNESDAY AFTERNOON REMAINS
WELL WEST AND 500MB HEIGHTS ARE PROGGED TO REMAIN STABLE THROUGH
THE DAY. THERE IS SOME WEAK SURFACE CONVERGENCE...WITH A
DEVELOPING BUT WEAK WARM FRONT MOVING NORTHWARD ACROSS THE AREA
DURING THE AFTERNOON. SREF MEMBERS AND OPERATIONAL MODELS ARE
PRETTY EVENLY SPLIT BETWEEN BREAKING OUT SCATTERED STORMS ON
WEDNESDAY AFTERNOON AND KEEPING THE AREA DRY UNTIL THE EVENING.
HAVE KEPT SLIGHT CHANCE TO LOW CHANCE POPS IN EASTERN NEBRASKA FOR
NOW TO CAPTURE THE POTENTIAL FOR A COUPLE OF STORMS TO DEVELOP. IF
STORMS CAN GO UP AND SUSTAIN THEMSELVES...0-6KM BULK SHEAR IS
ADEQUATE TO SUPPORT SUPERCELLS WITH A LARGE HAIL/DAMAGING WIND
THREAT...AND 0-1KM SHEAR OF AROUND 20 KTS AND HODOGRAPHS WITH
STRONG CLOCKWISE CURVATURE WOULD SUPPORT A TORNADO THREAT AS WELL.
LATER IN THE EVENING...HIGHER COVERAGE OF STORMS SHOULD BREAK OUT
ALONG THE ELEVATED WARM FRONT IN NORTHEAST NEBRASKA/NORTHWEST
IOWA...WITH THE THREAT OF ELEVATED HAILERS IN THE EVENING BEFORE
THE STORMS SHIFT NORTHEASTWARD OUT OF THE AREA.
SOUTHWESTERLY MID-LEVEL WINDS PUSH WARMER TEMPERATURES INTO THE AREA
ON THURSDAY JUST AHEAD OF THE SURFACE LOW...AND MOISTURE IS PROGGED
TO DECREASE. THUS...HAVE NUDGED TEMPS UP JUST A BIT ON
THURSDAY...CLOSER TO 850MB MIX-DOWN TEMPS. BOTH THURSDAY AND
THURSDAY NIGHT SHOULD REMAIN DRY GIVEN DRIER PROFILE AND STOUT CAP.
MADE NO CHANGES FRIDAY AND BEYOND.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
CONVECTION IS MOVING EAST OF THE TAF SITES THIS MORNING AND SHOULD
BE CLEAR OF ALL SITES BY 12Z. A SMALL BAND OF MVFR CIGS ARE
FOLLOWING THE CONVECTION. THIS SHOULD ALSO CLEAR BY EARLY THIS
MORNING WITH JUST SOME MID AND HIGH LEVEL CLOUDS REMAINING.
TERMINALS SHOULD REMAIN DRY THEN THE REST OF THE CYCLE WITH SURFACE
HIGH BUILDING INTO THE REGION. WILL LIKELY SEE WEST AND NORTHWEST
WINDS INCREASE AT THE TERMINALS THIS MORNING AND CONTINUE INTO EARLY
AFTERNOON BEFORE GOING LIGHT AND VARIABLE TONIGHT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
MAYES/BOUSTEAD