000
FXUS63 KGID 131051
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
551 AM CDT MON MAY 13 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON MAY 13 2013

THE BIG STORY TODAY WILL BE THE QUICK WARM UP WITH HOT CONDITIONS
EXPECTED.

IR SATELLITE DATA SHOWS WIDESPREAD CLOUDINESS SPILLING
SOUTH THROUGH THE NORTHERN AND CENTRAL PLAINS. FORECAST MODELS
INDICATE THESE HIGH CLOUDS SHOULD BE WITH US THROUGH MUCH OF THE
DAY. HOWEVER...THESE CLOUDS ARE FAIRLY THIN SO EXPECT A GOOD DEAL
OF SUNSHINE TO STILL PENETRATE DOWN TO THE SFC AIDING OUR WARM UP.

THE BIGGEST FACTOR IN THIS WARM UP IS THE HUGE UPPER LEVEL RIDGE
LOCATED OVER THE WESTERN CONUS THAT IS SLIDING EAST INTO THE
PLAINS TODAY. THIS IS BRINGING IN SOME MUCH WARMER AIR ALOFT. FOR
INSTANCE...850MB TEMPERATURES ALONG HIGHWAY 281 ARE EXPECTED TO
RISE FROM AROUND 4C AT 18Z YESTERDAY TO 19C AT 18Z TODAY. THERE
WILL ALSO BE STRONG MIXING TODAY WEST OF HIGHWAY 281 TO AROUND
650MB...WHICH SHOULD HELP DRY OUT THE AIR AND WARM TEMPERATURES. A
BIT OF A WEAK INVERSION MAY PERSIST ACROSS EASTERN ZONES...THUS
LIMITING MIXING AND KEEPING TEMPERATURES SEVERAL DEGREES COOLER.
MOST OF OUR FORECAST AREA WILL ALSO SEE A BREEZY SOUTHWEST WIND
THIS AFTERNOON...WHICH ALSO FAVORS WARMER AND DRIER AIR.
THEREFORE...WILL CALL FOR HIGHS IN THE 90S TODAY WEST OF HIGHWAY
281 WITH MID TO UPPER 80S EAST OF HIGHWAY 281. WE HAVE ALSO
INCREASED WIND SPEEDS THIS AFTERNOON A TOUCH ABOVE THE AVERAGE
MODEL GUIDANCE VALUES WHILE DECREASING DEWPOINTS A BIT BELOW THE
AVERAGE MODEL GUIDANCE DUE TO STRONG MIXING.

TONIGHT...THE WARMING CONTINUES WITH 850MB TEMPERATURES EXPECTED
TO RISE INTO THE 24C OR 25C RANGE ACROSS THE CWA. THIS WILL RESULT
IN SFC LOW TEMPERATURES IN THE UPPER 50S TO NEAR 60 ACROSS THE
FORECAST AREA. DRY CONDITIONS WILL CONTINUE BENEATH THE UPPER
LEVEL RIDGE.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON MAY 13 2013

MAIN STORY: A DECIDELY MORE SUMMERLIKE PATTERN WILL CONTINUE...
CLIMAXING WITH SUBSTANTIAL HEAT TUE FOLLOWED BY MULTIPLE TSTM
CHANCES. TEMPS WILL AVERAGE ABOVE NORMAL THRU SAT WITH MUCH ABOVE
NORMAL TUE. THIS PATTERN COULD END WITH SVR TSTMS NEXT WEEKEND.

ALOFT: WARM ZONAL FLOW TUE-WED OVER THE NRN USA WILL MODERATELY
AMPLIFY THU-FRI AS A TROF MOVES INTO THE W. SAT-SUN THE TROF MOVES
ONTO THE PLAINS WITH ASSOCIATED HGT FALLS DIRECTING THE EXIT REGION
OF AN 80 KT ULJ INTO THE CNTRL PLAINS.

SFC: DEEP LOW PRES WILL BE ADVANCING ACROSS SRN CANADA TUE-WED. ITS
ASSOCIATED COOL FRONT WILL MOVE THRU HERE TUE NGT AND BECOME QUASI-
STATIONARY OVER NRN KS. AS THE UPR TROF APPROACHES...THIS FRONT
COULD HEAD BACK N AS A WARM FRONT...AND BE OVER NRN NEB FRI. THE
DRYLINE WILL ALSO INTENSIFY.

HAZARDS: NOTHING DEFINABLE AT THIS POINT BUT MULTIPLE CHANCES FOR
TSTMS EXIST TUE NGT-SAT. IT/S TOO EARLY TO PIN DOWN LOCATION/TIMING/
COVERAGE AND INTENSITY...BUT ODDS ARE INCREASING THAT WE COULD HAVE
TO DEAL WITH AT LEAST ONE EPISODE OF SEVERE.

THE DAILY DETAILS...

TUE: SUNNY AND HOT WITH NEAR RECORD HIGH TEMPS OF 93-99F. +26C AT H8
AND 582 HGTS AT H5. H8 TEMPS 2 STANDARD DEVIATIONS OR ROUGHLY 25F
ABOVE NORMAL. GRI AND HSI WILL BE WITHIN 1-2F OF RECORDS.
GRI 99-1941. HSI 97-1941.

COULD SEE A LATE AFTN TSTM OVER S-CNTRL NEB.

SEVERE: AS NOTED BY SUN DAY SHIFT...FCST SOUNDINGS HAVE BEEN
CONSISTENTLY SHOWING INVERTED-V SIGNATURE WITH A LARGE DRY ADIABATIC
SUB-CLOUD LAYER. PRECONVECTIVE DCAPE IS FCST BETWEEN 1200-1800 J/KG.
WHILE RISK OF A TSTM IS VERY LOW AT ANY ONE LOCATION...ANY STORMS
THAT DEVELOP WILL BE CAPABLE OF PRODUCING DAMAGING MICROBURST WINDS.

FIRE WX: PENDING EVALUATION OF FUEL STATUS LATER TODAY...A RED FLAG
WARNING MAY BE NEEDED. WHILE RH WILL BE CRITICAL /OR NEAR CRITICAL/
OVER ALL OF S-CNTRL NEB AND N-CNTRL KS...WINDS SHOULD ONLY BE A
PROBLEM SE OF A LINE FROM PLAINVILLE KS-GENEVA NEB. THIS IS WHERE
THE POTENTIAL FOR A RFW EXISTS.

TUE NGT: COOL FRONTAL PASSAGE. IT/S PROBABLY DRY MOST LOCATIONS. THE
THREAT FOR AN ISOLATED TSTM WILL CONTINUE OVER S-CNTRL NEB.

THIS COOL FRONT WILL END THE HEAT...BUT TEMPS WILL STILL REMAIN
8-15F ABOVE NORMAL WED-SAT.

WED: POSSIBLY A LEFT-OVER SHWR OR TSTM ALONG THE FRONT? OTHERWISE
DRY AND NOT AS HOT...BUT STILL SEVERAL DEGS ABOVE NORMAL.

ZONAL FLOW AND RISING HGTS OVER THE ERN USA WILL SET THE STAGE FOR
TSTM POTENTIAL OVER OR NEAR THE FCST AREA. HIGH PRES WILL PARK OFF
THE CAROLINA COAST WITH SEVERAL DAYS OF UNINTERRUPTED NWD GULF MSTR
TRANSPORT INTO THE PLAINS.

WED NGT-SAT: OVERALL AVERAGES P/CLOUDY AND DRY MOST OF THE TIME.
HOWEVER...THE FRONT...DRYLINE AND THEIR INTERSECTION WILL ALL BE
CAPABLE OF TSTM DEVELOPMENT WITH THE APPROACH OF WEAK PV ANOMALIES
OUT OF THE WRN USA TROF. WE/LL ALSO NEED TO WATCH NOCTURNAL LLJ
DEVELOPMENT FOR CONVECTIVE INITIATION.

DEEP LAYER SHEAR WILL BE 20 KTS OR LESS THRU FRI NGT. SO ANY TSTMS
THAT DEVELOP WILL TAKE THE FORM OF MULTICELL CLUSTERS WITH POTENTIAL
FOR MCS ACTIVITY.

FRI AN ELEVATED MIXED LAYER /EML/ WILL ADVECT ONTO THE PLAINS...AND
SHOULD CAP ALL TSTM DEVELOPMENT...ESPECIALLY IF WARM FRONT LIFTS N
OF THE FCST AREA. SO WE MAY BE ABLE TO REMOVE SOME POPS EVENTUALLY.
THE CAP SHOULD HOLD UNTIL DYNAMIC FORCING INCREASES AND LOW PRES
EJECTS OFF THE FRONT RANGE SOMETIME SAT OR SAT NGT. SEVERE TSTMS
COULD ERUPT AS THIS OCCURS GIVEN THE RICH MSTR AND INSTABILITY THAT
WILL BE IN PLACE. 0-5 KM SHEAR IS FCST TO INCREASE. NEW SWOD48 IS
SUPPORTIVE OF SVR POTENTIAL AND HAS MOST OF THE FCST AREA OUTLOOKED.

SUN: PROBABLY DRY OR BECOMING DRY AS LOW PRES EXITS TO THE NE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 545 AM CDT MON MAY 13 2013

VFR CONDITIONS ARE EXPECTED THROUGH THE TAF VALID PERIOD.
SCATTERED HIGH CLOUDS ARE RIDING OVER THE RIDGE AND INTO KGRI THIS
MORNING...WHICH SHOULD CONTINUE THROUGH MOST OF THE DAY WITH
THINNING CLOUDS THIS EVENING. THE SFC WIND WILL VEER WITH TIME
TODAY BECOMING MORE NORTHWESTERLY AND GUSTY AT TIMES AS STRONGER
WINDS MIX TO THE SFC DURING THE LATE MORNING INTO THE EARLY
AFTERNOON TIME FRAME. HOWEVER...A SFC TROUGH MAY MAKE IT AS FAR
SOUTH AS KGRI BY MID AFTERNOON AND THEN WASH OUT. THIS WOULD TURN
THE WINDS TO A MORE WESTERLY OR EVEN NORTHWESTERLY DIRECTION AND
THE WIND WOULD BE LIGHTER. EXPECT SOUTHWESTERLY WINDS AGAIN BY
TONIGHT WITH THAT SFC TROUGH EVENTUALLY WASHING OUT.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...WESELY
LONG TERM...HALBLAUB
AVIATION...WESELY