FXUS63 KLBF 292109
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
310 PM CST SUN NOV 29 2009

.SYNOPSIS...
H5 SPLIT FLOW CONTINUES TDY WITH SWRLY FLOW ACROSS THE BULK OF THE 
SRN CONUS AND A CLOSED LOW OVER SWRN AZ. NRN STREAM HAD A RIDGE OVER 
WRN CANADA A TROUGH OVER THE UPPER MIDWEST AND ERN CANADA. AT THE 
SURFACE...HIGH PRESSURE HAS BUILT INTO NRN ROCKIES TDY WITH LIGHT 
WESTERLY WINDS AND CLEAR SKIES. READINGS WERE IN THE 40S AS OF 2 PM 
CST. 

.DISCUSSION...

NEAR TERM...TONIGHT THROUGH WEDNESDAY...A DRY ARCTIC FROPA ON 
TUESDAY WILL HIGHLIGHT THE NEAR TERM WEATHER CONCERNS THROUGH 
WEDNESDAY. FOR TONIGHT...BASED ON MIN TEMPS THIS MORNING...EXPECTED 
LIGHT WESTERLY WINDS TONIGHT AND DRY BOUNDARY LAYER AIR...DECIDED TO 
GO WITH THE COOLER MAV GUIDANCE FOR TONIGHT WHICH ACTUALLY PERFORMED 
BETTER WITH MIN TEMPS EARLIER THIS MORNING. DECIDED ONCE 
AGAIN...GIVEN THE LIGHT WESTERLIES AND BONE DRY BOUNDARY LAYER 
CONDS...TO INCLUDE SOME COOLER LOWS IN THE PLATTE RIVER VALLEY. THIS 
RESULTS IN LOWS IN THE MID TEENS FOR THE PLATTE RIVER VALLEY. 
SHIFTING GEARS TO MONDAY...SHOULD BE THE WARMEST DAY OF THE PERIOD 
WITH LIGHT WESTERLY WINDS AND WARMER H85 TEMPS RANGING FROM 5 TO 8C 
TOMORROW AFTERNOON. WENT WITH HIGHS IN THE UPPER 50S TO AROUND 
60...WHICH REFLECTED THE WARMER MAV NUMBERS. 

BY TUESDAY...AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL TRAVERSE SRN 
CANADA. THIS FEATURE WILL FORCE A COLD FRONT INTO WESTERN AND NORTH 
CENTRAL NEBRASKA DURING THE DAY ON TUESDAY. DROPPED HIGHS FOR 
TUESDAY SLIGHTLY BASED ON EARLIER TIMING OF THE FRONT AND RESULTANT 
COOLER GUIDANCE. NONE THE LESS...HIGHS TUESDAY WILL STILL BE ABOVE 
NORMAL WITH READINGS IN UPPER 40S TO AROUND 50. ARCTIC AIR WILL PUSH 
INTO THE AREA TUESDAY NIGHT RESULTING IN LOWS IN TEENS AND LOWER 20S 
AND HIGHS IN THE MID 30S FOR WEDNESDAY. 
 
LONG TERM...THURSDAY THROUGH SUNDAY...AS WAS THE CASE 
YESTERDAY...THE EXTENDED FORECAST REMAINS PROBLEMATIC AS LITTLE 
AGREEMENT NOTED BETWEEN THE NOAM AND EURO EXTENDED SOLNS THIS 
MORNING FOR LATE IN THE WEEK. H5 SPAGHETTI ENSEMBLE PLOTS THIS MORNING 
NOT MUCH HELP EITHER AS LARGE SPREAD IS PRESENT IN BOTH THE NAEM 
AND ECM PLOTS BEYOND THURSDAY NIGHT. A QUICK GLANCE AT THE 12Z GFS 
FOR NEXT WEEKEND AND 00Z EURO FROM LAST NIGHT ARE INDICATING SOME 
RIDGING BUILDING INTO THE GULF OF ALASKA AND A RESULTANT TROUGH 
ACROSS THE CENTRAL AND WESTERN CONUS NEXT WEEKEND. THOUGH SIMILAR 
IN CONCEPT...TIMING AND DEGREE OF THE ARCTIC SURGE STILL VERY MUCH 
UP IN THE AIR. WITH THIS UNCERTAINTY...GENERALLY FOLLOWED 
PERSISTENCE...WHICH WAS TO INCREASE CLOUD COVER...WSW FLOW 
ALOFT...AND TO GO WITH TEMPS AOB CLIMO HEDGING ON INCREASED CLOUD 
COVER AND A POSSIBLE ARCTIC SURGE NEXT WEEKEND.  

&&

.AVIATION...
VFR CONDITIONS SHOULD DOMINATE FORECAST WITH ONLY MID LEVEL SCT-BKN 
DECK AOA 7KFT AGL PROGRESSING ACROSS CENTRAL NEBRASKA THIS EVENING. 
WINDS SHOULD REMAIN LIGHT WESTERLY THROUGH THE NIGHT AND WITH 
MINIMAL WINDS ALOFT LLWS SHOULD BE PROHIBITED 

&&

.LBF WATCHES/WARNINGS/ADVISORIES...NONE

$$

.SHORT AND LONG TERM...BUTTLER
.AVIATION...DP