738 
FXUS63 KLBF 191855
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
155 PM CDT SAT APR 19 2003

CHANCE OF PRECIPITATION THROUGH THE FORECAST PERIOD FIRST CONCERN...
WITH CLOUDS AND AFFECTS ON TEMPERATURES A SIDE NOTE.

DOUBLE BARREL H85 LOWS CURRENTLY IMPACTING THE CENTRAL CONUS...WITH 
ONE OVER WESTERN OKLA AND ANOTHER OVER SOUTHWEST MINN. STRONG 
THUNDERSTORMS IN DEEP TROPICAL MOISTURE PLUME (THETA-E AXIS) ACROSS 
THE LOWER MISS AHEAD OF OKLA LOW. SCATTERED SHOWERS AND STORMS 
REMAINING IN WESTERN KANSAS AND EASTERN COLO NORTH OF H85 LOW ALONG
LOW LEVEL BOUNDARY. CURRENTLY ONLY PRECIPITATION ACROSS CWA IN NEAR 
IMPERIAL...OTHERWISE MID LEVEL SUBSIDENCE UNDER LEFT ENTRANCE REGION 
OF JET KEEPING REMAINDER OF THE CWA PRECIPITATION FREE. SOME BREAKS 
IN LOW OVERCAST CEILING NOTED ON VIS SAT...BUT SHORT-LIVED.

H50 LOW OVER EASTERN NORTH DAKOTA WILL REGRESS SOUTHWEST INTO 
CENTRAL SOUTH DAKOTA THIS EVENING. VORT MAX SWINGING SOUTHEAST 
THROUGH THE BASE OF THE UPPER TROUGH WILL ALLOW ISOLATED OR
SCATTERED RAIN SHOWERS TO MOVE INTO THE NORTHERN PORTIONS OF THE CWA 
LATE THIS EVENING AND PERSIST OVERNIGHT. WILL KEEP CHANCE GOING IN 
THE NORTHEAST THROUGH EARLY IN THE AFTERNOON UNTIL UPPER LOW EJECTS
NORTHEAST OVER THE UPPER MIDWEST AND DRIER AIR MOVES IN FROM THE 
WEST. WILL KEEP PRECIPITATION TYPE IN LIQUID FORM...BUT A FEW SNOW 
FLAKES MAY MIX IN LATE TONIGHT/EARLY SUNDAY MORNING WITH FREEZING 
TEMPERATURES ONLY ABOUT 2000 FEET ABOVE THE GROUND.

WINDY EARLY SUNDAY AS TIGHT PRESSURE GRADIENT SETS UP LATE TONIGHT 
BETWEEN HIGH PRESSURE BUILDING OVER THE CENTRAL HIGH PLAINS AND 
SURFACE LOW PRESSURE OVER WISCONSIN. GRADIENT RELAXES BY EARLY 
AFTERNOON...AND NOTHING INDICATES WIND ADVISORY CRITERIA BEING MET 
AT THIS TIME. SLIGHTLY WARMER ON MON AS RIDGE BEGINS TO BUILD IN THE 
WEST. WILL ONLY NEED TO TWEAKS TEMPERATURES FIRST FIVE PERIODS AS 
MODELS STILL IN GOOD AGREEMENT WITH TRANSITION.

TUES AND WEDS...WEATHER PATTERN WILL REMAIN ACTIVE OVER THE CONUS 
WITH TWO SIGNIFICANT STORMS IMPACTING THE NORTHERN CALIFORNIA COAST 
LATER THIS WEEK. ETA STILL BUILDING A HIGHLY AMPLIFIED RIDGE OVER 
THE CENTRAL PLAINS THROUGH TUES...WITH THE GFS WEAKER AND WANTING TO 
BRING CONVECTIVE COMPLEX OVER THE RIDGE AXIS AND THROUGH THE 
FORECAST AREA TUESDAY AFTERNOON. ETA SIMILAR...BUT KEEP CONVECTION 
CONFINED TO THE SOUTHERN PLAINS. NOT SURE WHICH TO BELIEVE...SO WILL 
LEAVE CHANCE OF THUNDERSTORMS IN THE FORECAST FOR TUESDAY AFTERNOON 
ALL BUT NORTHEAST CWA. MAIN TROUGH TO IMPACT THE AREA WEDNESDAY AND 
WEDNESDAY NIGHT WITH STRONG THUNDERSTORMS POSSIBLE WITH NEGATIVE 
TILT TO SYSTEM AND HINT OF STRONGLY SHEARED ENVIRONMENT. MENTIONED 
THIS IN THE HWO AS WELL.

DAYS 5 THROUGH 7...WARP AROUND CLOUDS AND SCATTERED SHOWERS ON 
BACKSIDE OF SYSTEM SHOULD PREVAIL IN THE WEST INTO THURSDAY...WITH 
CHANCE OF THUNDERSTORMS EAST CWA IN THETA-E RIDGE AXIS. WHILE 
THUNDERSTORMS IN THE EAST WERE CONSISTENT WITH PREVIOUS FORECAST...
ADDED SHOWERS WEST TO BLEND WITH SURROUNDING OFFICES. TRANSITION 
FRIDAY AS RIDGE BUILDS ONCE AGAIN IN ADVANCE OF NEXT UPPER TROUGH TO 
IMPACT THE REGION OVER THE WEEKEND ACCORDING TO THE GFS. FELT 
OBLIGED TO ADD THUNDER DAY 7.

.LBF...NONE

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