Severe Thunderstorm Warning 102, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
310 AM CDT WED JUN 10 1998

...FORECAST PROBLEMS THIS MORNING ARE THE ENDING OF THE PRECIPITATION
TODAY AND THE POSSIBLE RETURN TONIGHT...ESPECIALLY IN THE WEST...

IN THE FIRST PERIOD...
KLNX WSR-88D INDICATES THAT THUNDERSTORMS ARE MAINLY NORTH OF A LINE
FROM CHAPPEL THROUGH NORTH PLATTE TO BROKEN BOW. SO...THUNDERSTORMS
SHOULD BE INCLUDED IN THE NORTH CENTRAL AND NORTHWEST ZONES AT LEAST
THIS MORNING. THE REST OF THE AREA WILL PROBABLY NOT HAVE ANY SHOWERS
OR THUNDERSTORMS BEFORE LATE THIS AFTERNOON OR EARLY EVENING.

TURNING TO THE MODEL PERFORMANCE...NGM/AVN HAD GOOD INITIALIZATION.
HOWEVER, THE OUTPUT FROM YESTERDAY MORNING'S AVN WAS DOING BEST WITH
500MB HEIGHT AND VORTICITY FIELDS. THE SOLUTIONS OF THE TWO WERE
SIMILAR THROUGH 36 HOURS. BY 36 HOURS, THOUGH, THE NGM WAS STRONGER
WITH THE NEXT SHORT WAVE THAN WAS THE AVN. IN FACT, THE NGM INDICATES
FAIRLY STRONG CYCLONIC VORTICITY ADVECTION AND SOME QG FORCING IN THE
850-500MB LAYER IN CENTRAL AND WESTERN NEBRASKA BY 12Z THURSDAY.
HOWEVER, WITH LOW MIXING RATIO (MEAN VALUES OF 4-5 G/KG IN THE
850-700MB LAYER), MEAN RH IN THAT LAYER OF 30 PERCENT, AND 850
DEWPOINTS OF 0-4C, ANY STORMS THAT DO DEVELOP WILL PROBABLY BE
HIGH-BASED WITH ONLY LIGHT PRECIPITATION REACHING THE SURFACE. GUSTY
WIND WILL PROBABLY BE THE MAIN WEATHER PROBLEM WITH STORMS THAT
DEVELOP. THEREFORE, WOULD SUGGEST BACKING OFF SOME ON THE PROBABILITY
OF MEASURABLE PRECIPITATION TODAY AND TONIGHT IN THE WESTERN HALF OF
THE FORECAST AREA AND BACKING OFF TONIGHT IN THE NORTH CENTRAL PARTS.
THE FORCING CONTINUES OVER NORTH CENTRAL ZONES INTO THURSDAY; BUT, SO
DOES THE DRY LOW LEVEL.

AT 36 HOURS, THE BOUNDARY LAYER RH IS EXPECTED TO BE 70 PERCENT OR
HIGHER SOUTH OF A SNY-OGA-LBF LINE. WITH RESIDUAL LOW LEVEL MOISTURE
FROM YESTERDAY EVENING'S THUNDERSTORMS, THE HIGHER BOUNDARY LAYER RH
SHOULD BE MORE WIDESPREAD THAN THAT. HOWEVER, WITH WESTERLY COMPONENT IN
THE WIND DIRECTION, FOG IS NOT LIKELY.

TURNING ATTENTION TO TEMPERATURES, THE 1000-500MB THICKNESS FORECAST
INDICATES INCREASES OF 60M TODAY WITH LITTLE CHANGE THURSDAY. THE 850MB
TEMPERATURE INCREASE WILL RANGE FROM 5C IN THE SOUTHWEST TO 10C IN THE
NORTH CENTRAL TODAY WITH LITTLE OR NO CHANGE THURSDAY. THAT SHOULD GIVE
NUMBERS OF AROUND 80 TODAY IN THE SOUTHWEST TO AROUND 75 IN THE NORTH
CENTRAL AND NORTHWEST.

SUGGESTED CCF

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECAST IS
CONTAINED WITHIN THE PRODUCT OMAZFPNE.

LBF BB 079/050 080/051 080 49131
VTN TB 075/052 077/054 078 49631

OGA BB 080/051 081/053 081 49131
IML BB 081/052 082/055 082 49131
BBW TB 076/053 078/055 078 466L33
ANW TB 074/053 075/055 077 49633
ONL TB 074/054 074/057 074 49633

SPRINGER

NEZ058-069-100705-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
143 AM CDT (1243 AM MDT) WED JUN 10 1998

...SMALL STREAM ADVISORY HAS BEEN ALLOWED TO EXPIRE...

THE SMALL STREAM ADVISORY FOR SOUTHEAST PERKINS AND NORTHEAST
CHASE COUNTIES HAS EXPIRED. AT 130 AM CDT (1230 AM MDT) NORTH
PLATTE DOPPLER RADAR INDICATED THAT RAIN HAD ENDED ACROSS SOUTHWEST
NEBRASKA. NO REPORTS OF FLOODING HAVE BEEN REPORTED FOR ALONG
STINKING WATER CREEK. ADDITIONAL THUNDERSTORMS DEVELOPING
FURTHER WEST MAY PROVIDED MORE RAINFALL LATER TONIGHT.

INDIVIDUALS LIVING NEAR AND ALONG STINKING WATER CREEK FROM NEAR
MADRID SOUTH INTO NORTHEAST CHASE COUNTY SHOULD REMAIN ALERT. IF
TRAVELING ON THE BACK ROADS BE ALERT FOR STANDING WATER ON COUNTY
ROADS.

IF ANY FLOODING IS OBSERVED CONTACT YOUR LOCAL LAW ENFORCEMENT FOR
RELAY OF INFORMATION TO THE NATIONAL WEATHER SERVICE.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY AND THE ROAD BENEATH MAY NOT BE INTACT.  VEHICLES
CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.  IT ONLY TAKES
A FOOT OR TWO OF FLOWING WATER TO WASH MOST CARS AWAY.

WOOD