Severe Thunderstorm Warning 244, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
119 PM CDT SUN AUG 20 2000

...FORECAST CHALLENGE TO BE PCPN PLACEMENT TONIGHT AND MONDAY
NIGHT...AND LOW CLOUDS...

MODEL RUNS FAIRLY CONSISTENT WITH PREVIOUS RUNS...AND FOR THE MOST
PART...SIMILAR.  AVN BRINGS PCPN FARTHER SOUTH INTO OUR CWA...
NGM KEEPS IT FARTHER NORTH...SO ETA IN BETWEEN.WILL PROBABLY USE
AN ETA/AVN COMPROMISE FOR FORECAST. H7 OMEGA FIELDS LIMIT PCPN TO
CURRENT AREA FOR THE MOST PART...EXCEPT FOR EXPANSION EASTWARD IN
NORTHERN TIER.  MAIN DEVELOPMENT TO BEGIN NEAR BLACK HILLS 00Z MON...
SPILLING OVER INTO OUR NORTHWEST ZONES SHORTLY AFTER AND TRACKING
EASTWARD THRU 12Z. OMEGA FIELDS AT H7 SHIFT SOUTHWARD THOUGH AS UPR
LVL DIV SHIFTS TO NE SD AT 06Z. A LITTLE H2 DIV SHOWS UP OVR LBF BY
12Z THO...SUGGESTING SHRA MAY MAKE IT FARTHER SOUTH THAN ETA QPF
FIELDS WOULD INDICATE. LATEST SWODY1 ENCOMPASSES THIS AND FEEL THE
SLGT RISK IS WELL PLACED. QUESTION IS...HOW FAR SOUTH WILL THE NON-
SVR SHRA/TSRA GO.  PCPN IS ALREADY INTO NE COLORADO.  WHATEVER
DOESNT HAVE PCPN AT ZFP ISSUANCE TIME WILL HAVE POPS.

BL RH ON ETA SUGGESTS SOME LEFTOVER CLOUDS ACROSS MOST OF CWA
MONDAY...ADD SOME LAPSE RATES OF 7 OR MORE DURING MONDAY AFTERNOON
AND THAT PUTS IN A GOOD CHANCE OF CU ALSO.  LOW CLOUDS AND STRATUS
ARE FORECAST BY ETA FOR ANW-ONL AREA MONDAY MORNING. THIS LOOKS
REASONABLE WITH PCPN A PRETTY GOOD CHNC TNT THERE AND MOISTURE
POOLING THERE. NGM BRINGS FOG AND STRATUS RIGHT BACK INTO LBF THO TOO
ON NE WINDS. WILL MENTION LOW CLOUDS AND PATCHY FOG FOR THE MORNING
PERIOD MONDAY.  PARTLY TO MOSTLY SUNNY MOST PLACES BY AFTERNOON.
HIGH TEMPS ARE FORECAST TO RANGE FROM 75 TO 80 OR THEREABOUTS FOR
MOST LOCATIONS.

MONDAY NIGHT...NEXT SYSTEM/TROF ENTERS BY 00Z TUES. THINGS LOOK
LIKE THEY WILL FIRE IN OUR CWA BY 03Z.  LOTS OF THINGS COMING
TOGETHER OVER CENTER OF CWA (UPR LVL DIV...H7 OMEGA...MOISTURE)
SUGGEST ALL LOCATIONS HAVE GOOD CHNC OF GETTING PCPN MONDAY NIGHT AS
MCS TYPE SYSTEM DEVELOPS AND MOVES EAST. LOW CLOUDS TO BLANKET AREA
ONCE AGAIN TUESDAY MORNING IN ITS WAKE OVER OUR CWA AS SYSTEM MOVES
EAST.

TUESDAY...HIGH TEMPS WILL DEPEND A LOT ON HOW STUBBORN LOW CLOUDS
WILL BE.  SOUTHEAST WINDS AT SFC GIVE ME LITTLE CONFIDENCE THAT
ANYWHERE EXCEPT FRINGES WILL BREAK OUT OF CLOUDS MUCH BEFORE 00Z. 80
TO 85 IS THE GOING FORECAST...AND SHOULD BE A SAFE RANGE TO USE.

EXTENDED WED/THU/FRI...WILL EXTEND SLGT CHNCS TO FRI PER MEX OUTPUT.
MRF HAS SFC LOW EJECTING INTO SW NEB WED MORN WITH SCT PCPN ALONG SRN
NEB...PRESUMABLY IN VCNTY OF FRONT. LOW STAYS PUT THRU 00Z THU AND
DRIFTS SLIGHTLY NORTH BY 12Z THU...WOBBLING BACK SOUTH TOWARD GLD BY
12Z FRI. NORMALLY THIS WOULD MEAN PCPN CHNCS...BUT WITH UPPER LEVEL
RIDGE SITTING OVER US ALSO...CHNCS ARE DIMINISHED DESPITE GOOD
SHORTWAVE TROF CROSSING CANADA THURSDAY...TRYING TO EXTEND SOUTH INTO
AREA. WITH LOW STUCK IN THE VCNTY AT SFC..ANY OMEGA THAT MIGHT MAKE
IT INTO AREA WILL PERHAPS KICK OFF WDLY SCT SHRA...SO WORDING OF
SLIGHT CHANCES LOOKS OK.

.LBF...NONE

SLM