Severe Thunderstorm Warning 51, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
200 PM CDT WED MAY 20 1998

CHANCES FOR SVR TSRA AND THEN TEMPS ARE STILL THE MAIN CONCERNS...

18Z SFC ANALYSIS OF WIND FIELD SHOWS STATIONARY FRONT LOCATED ACROSS
THE WRN PANHANDLE INTO NWRN KS...EWD INTO NRN MO. WINDS REMAIN WEAK
ALONG THE FRONT...BUT IN NC NEBR AND THE PANHANDLE HAVE PICKED UP SOME.
STORMS ALREADY GOING IN ERN WY ATTM AND WILL HAVE TO WATCH THESE AS THEY
MOVE INTO THE NRN PNHANDLE.

SUMMERTIME WX PATTERN CONTINUES WITH UPPER TROF BEGINNING TO MOVE
ONSHORE IN THE W. NGM SEEMS A LITTLE TOO FAST WITH THIS UPPER SYSTEM.
FOR CONVECTION PURPOSES...HARD TO FIND UPPER FORCING WITH THIS TYPE OF
PATTERN...BUT IT WONT TAKE MUCH. FOR TONIGHT...JET AXIS AT 250 MB RUNS
ACROSS THE PANHANDLE BY 00Z THU. UPPER DIVERGENCE ASSOCIATED WITH THIS
JET IS PROGGED TO TRACK ACROSS SRN SD THRU THE EVENING. ETA BECOMES
CONTAMINATED IN THE 200-300 MB LAYER BY 06Z THU WITH CONVECTIVE
FEEDBACK...BUT THIS MAY BE A GOOD INDICATION OF WHERE THE MODEL THINKS
A CONVECTIVE SYSTEM WOULD BE AT THIS TIME. REGARDLESS...STORMS
DEVELOPING OVER THE FRONT RANGE ALREADY AND SINCE THEY SEEM TO BE DOING
SO OVER A WIDE RANGE...WOULD SUSPECT THAT THERE IS SOME SORT OF SHORT
WAVE HIDDEN IN THE FLOW. SOME INDICATION OF THIS POSSIBLE AS WELL IN
WATER VAPOR LOOPS. ATMOSPHERE IN THE CENTRAL AND EASTERN PART OF THE
STATE IS LIKELY STILL RECOVERING FROM OVERNIGHT CONVECTION...BUT TEMPS
IN THE NRN PANHANDLE WARMING SIMILAR TO YDAY...WITH DEW POINTS THERE
ABOUT 5-6 DEGREES HIGHER. AS TEMPS NEAR CONVECTIVE TEMP...WOULD EXPECT
CONTINUED DEVELOPMENT IN THE HIGHER TERRAIN OF THE PANHANDLE INTO SWRN
SD BY LATE AFTERNOON. THEN...CORFIDI VECTORS WOULD SUGGEST A ERN
PROPAGATION OF A CONVECTIVE SYSTEM IF MCS DEVELOPS. GENERAL COOLING OF
THE UPPER LEVELS NOT INDICATED AT THIS TIME...HOWEVER CONTINUED
ISENTROPIC LIFT OVER THE PANHANDLE MAY ALLOW FOR SOME DYNAMIC COOLING
SIMILAR TO YDAY.

SIMILAR CONDITIONS SET UP FOR TOMORROW WITH FRONT MOVING LITTLE EXCEPT
FOR WHAT CONVECTION DOES TO IT. LOW LEVEL THETA-E MAX DOES SHIFT EWD
SOME ON THU...SUGGESTING INITIAL DEVELOPMENT MAY TAKE PLACE A LITTLE
FURTHER EWD INTO NC NEBR...BUT WITH MODELS HAVING A DIFFICULT TIME WITH
UPPER SUPPORT...WONT WORRY ABOUT PINNING LOCATION DOWN...BUT WITH
BETTER LIFT PROGGED BY 00Z FRI...WOULD EXPECT A SIMILAR SCENARIO. WILL
AGAIN GO WITH A BLEND OF GUIDANCE FOR TEMPS WITH LITTLE CHANGE IN THE
PATTERN EXPECTED. TEMPS WILL DEPEND HIGHLY ON AMOUNT OF CLOUD COVER
WITH LEFT OVER CONVECTION.

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE
CONTAINED WITHIN PRODUCT OMAZFPNE...

CCF
LBF BB 053/078 053/077 052 324
OGA BB 055/078 053/077 053 324
ONL BE 058/078 056/074 054 424
VTN BE 053/079 053/076 050 435

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