Severe Thunderstorm Warning 111, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
149 PM CDT TUE JUN 22 1999

...FORECAST CHALLENGE IS WHEN PCPN WILL END...

MODELS...IN PRETTY GOOD AGREEMENT. NGM HAD GOOD HANDLE ON SURFACE
FEATURES THIS MORNING...BUT WANTS TO FOCUS PCPN OVER NORTHWEST IOWA AT
00Z WED WHILE ETA FOCUSES OVER SOUTHEAST NEBRASKA. ETA IS MORE IN LINE
WITH REALITY IN MOS OTHER FEATURES. NOTICED GOOD THETA-E POOLING VIA
LAPS DATA ALONG AND EAST OF IML-VTN LINE WHERE CONVECTION HAD BEGUN
LATE THIS MORNING. SHOWERS DISSIPATED AS THEY MOVED INTO LOWER THETA-E
AIR...AWAY FROM SURFACE TROUGH. IMAGINE THETA-E RIDGE WILL BE A FOCUS
FOR ACTIVITY LATER TODAY ONCE FRONT MOVES IN.

...TONIGHT INTO WED MORNING...SHOWERS/THUNDERSTORMS LOOK PRETTY LIKELY
ALL OVER...BEGINNING IN THE NORTHWEST AND SPREADING EAST OVERNIGHT. LOWS
HAVE BEEN RUNNING HIGHER THAN GUIDANCE AND WILL LIKELY FOLLOW SUIT
TONIGHT EXCEPT FOR NORTHEAST ZONES WHERE A LITTLE COOLER AIR FILTERS IN
FIRST.  WILL THE PCPN PERSIST INTO WEDNESDAY? PERHAPS SOME STABLE PCPN
06-12Z WED WHEN SFC FIELDS INDICATE FRONT WILL BE SOUTH OF CWA BY 12Z.
WILL PUT IN LOW MORNING POPS FOR POSSIBLE LINGERING SHOWERS.

WEDNESDAY/NIGHT...COOLER TEMPS (UPR 70S LOW 80S) AS WE GET A BREAK FROM
THE ACTION DURING THE DAY. AS MORE EASTERLY UPSLOPE FLOW TAKES
PLACE...EXPECT POSSIBLE SHOWERS TO DEVELOP ANYWHERE OVER PANHANDLE AREA
LATE AND PROPOGATE EASTWARD DURING WED INTO THU OVERNIGHT HOURS. 40
POPS FOR WESTERN ZONES WED NIGHT...20 FOR NORTHEAST ZONES. FOR LOWS...
THINKING SOMETHING AROUND 62.

THURSDAY...FAIRLY FAST FLOW OVER FLAT RIDGE...LOOKS FAIRLY DRY...BUT
SOME CLOUDINESS. WOULD ANTICIPATE PRETTY GOOD REBOUND IN TEMPS TO
MID-UPR 80S AGAIN.

EXTENDED...MRF...ZONAL FLOW THURSDAY GIVES WAY TO WEAK SOUTHWEST FLOW
FRIDAY AS LOW/TROUGH DIGS INTO PACIFIC NORTHWEST AND LEE SIDE TROF
DEVELOPS.  GOOD WARM CAPPING THO (PER CHAT WITH HSI) AND LOOKS LIKE MOST
LIKELY TIMING FOR NEXT ROUND OF PRECIP WOULD BE SATURDAY LATE. BROAD
FLAT RIDGE BUILDS IN SUNDAY OVER HIGH PLAINS. FRIDAYS HIGH OF 95 FOR US
SEEMS A BIT OVERDONE EVEN IF WE DO SEE 27 C AT 850. WILL GO HIGHS UPPER
80S TO AROUND 90...LOWS LOWER TO MID 60S.

.LBF...NONE

SLM

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