FXUS63 KGLD 282006
AFDGLD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
206 PM MDT SAT JUN 28 2003

TONIGHT...CENTRAL PLAINS ON THE SOUTHERN FRINGE OF NORTHWESTERLY 
FLOW ALOFT. DISTURBANCE AT 18Z OVER NORTHERN IDAHO DIVING 
SOUTHEAST...AND WILL SPREAD UPPER LEVEL DIVERGENCE OVER THE ENTIRE 
FORECAST AREA BETWEEN 00Z AND 06Z. STRONG VORTICITY MAXIMUM FORECAST 
TO DEVELOP BY ALL SHORT TERM MODELS OVER EASTERN COLORADO AND BE 
LOCATED NEAR THE KANSAS/COLORADO BORDER AT 06Z (NGM A TAD FASTER). 
NOCTURNAL LOW LEVEL JET WILL DEVELOP DURING THIS TIME WITH WARM 
ADVECTION MAXIMIZED ALONG AND NORTH OF A SURFACE BOUNDARY WHICH WILL 
LIE GENERALLY ALONG I-70. THUNDERSTORM COMPLEX/MCS EXPECTED TO 
DEVELOP OVER NEBRASKA PANHANDLE AND MOVE INTO THE UNSTABLE 
ENVIRONMENT OF THE NORTHERN/EASTERN FORECAST AREA...WHERE BULK SHEAR 
VALUES OF 40 TO 50 KTS AND CAPE AXIS OF 1500-2500 J/KG WILL 
COINCIDE. WILL USE A YUMA TO COLBY TO GOVE LINE AS DIVISION BETWEEN 
CATEGORICAL/LIKELY POPS. THERE EXISTS A THREAT OF LOCALLY HEAVY 
RAINFALL...SCATTERED 1 TO 2 INCHES AND LOCALLY UP TO 3...ALL ZONES 
BUT COLORADO PER EXCESSIVE RAINFALL DISCUSSION AND PRECIPITABLE 
WATERS. AFTER 06Z...VORTICITY MAXIMUM WILL MOVE STEADILY 
EASTWARD...WITH LIFT MAXIMIZED IN THE EAST AND DIMINISHING IN THE 
WEST. LIKE THE ETA KAIN-FRITSCH UPDRAFT STRENGTH GRAPHICS DEPICTION 
FOR EVOLUTION/LOCATION OF CONVECTION DURING THIS TIME. 

SUNDAY...AT 12Z SHORTWAVE AXIS WILL LIE FROM HOLDREGE NEBRASKA TO 
HILL CITY TO GARDEN CITY...WITH LIFT/PRECIPITATION ONGOING EAST OF 
THE AXIS. MORNING POP GRADIENT IS DEPICTED ACCORDINGLY. ATTENTION 
THEN TURNS TO THE AFTERNOON AND EVENING. OUTFLOW BOUNDARIES SHOULD 
BE LINGERING ACROSS THE AREA FROM OVERNIGHT MCS. EASTERLY UPSLOPE 
SURFACE WINDS WILL ADVECT MOISTURE INTO THE REGION. HOWEVER...LATEST 
MODEL FORECASTS OF 700-500 MB LAPSE RATES ARE MARGINAL AT 
BEST...WITH ETA 6.5C/KM LINE JUST CLIPPING FAR WESTERN ZONES AND GFS 
JUST A LITTLE STEEPER AND FURTHER WEST. ETA KAIN-FRITSCH UPDRAFT 
GRAPHICS DEPICT CONVECTION SLIPPING FROM NORTHEAST TO SOUTHWEST 
ACROSS THE FORECAST AREA 18Z-21Z...THEN OUT OF THE AREA BY 
00Z...MOST LIKELY ALONG AN OUTFLOW BOUNDARY. CURRENT FORECAST 
DEPICTS THIS WELL AND ONLY MINOR ADJUSTMENTS REQUIRED. ONLY OTHER 
CONCERN WOULD BE FOR AFTERNOON CONVECTION MIGRATING OFF THE FRONT 
RANGE INTO COLORADO COUNTIES SUNDAY EVENING...BUT 0-6KM MEAN 
WIND/STORM MOTION WILL BE GENERALLY SOUTH SOUTHEAST...AND SEEMS 
UNLIKELY STORMS WILL MAKE IT THIS FAR EAST. 

MONDAY/TUESDAY...UPPER HEIGHTS BUILD FROM THE SOUTHWEST. ON 
MONDAY...AXIS OF POSITIVE 700 MB DEW POINTS/MOISTURE WILL BE IN 
PLACE OVER EASTERN COLORADO WITH SOUTHEAST UPSLOPE WINDS AT THE 
SURFACE. 700 MB TEMPERATURES ARE NOT PROHIBITIVELY LOW (7 TO 10C) 
AND 700-500 MB LAPSE RATES ARE GREATER THAN 7C/KM...SO WILL INSERT 
SLIGHT CHANCE FOR AFTERNOON/EVENING THUNDER MIGRATING INTO COLORADO 
COUNTIES. LOW/MID LEVELS DRY OUT CONSIDERABLY ON TUESDAY AND 700 MB 
TEMPERATURES RISE TO 16C. WILL LEAVE THIS DAY DRY AND HOT. 

EXTENDED (WEDNESDAY THROUGH SATURDAY)...STRONG 590-595 DAM ANTICYCLONE AT 
500 MB CENTERED OVER THE FOUR CORNERS WILL MOVE LITTLE DURING THE 
EXTENDED AND BE THE DOMINANT FEATURE. MAIN FORECAST PROBLEM FOR 
PRECIPITATION CHANCES WILL BE TO IDENTIFY SUBTLE SHORTWAVES EMBEDDED 
IN JET ON THE NORTHERN PERIPHERY OF THE RIDGE AND CAP STRENGTH IN 
SUPPRESSING CONVECTIVE INITIATION. CAP WILL BE TOO STRONG ON 
WEDNESDAY...BUT ON THURSDAY GFS FORECASTS A MODEST RISE IN 700 MB 
DEW POINTS AND SLIGHT COOLING OF 700 MB TEMPERATURES. FORECAST AREA 
WILL BE IN RIGHT ENTRANCE REGION OF JET/SHORTWAVE AT 500 MB GRAZING 
THE NORTHERN ZONES/AND SURFACE BOUNDARY SAGGING SOUTH...SO MENTION 
OF SLIGHT CHANCE STILL SEEMS WARRANTED. ON FRIDAY THE MOISTURE AXIS 
BACKS UP AND IS ORIENTED ALONG THE KANSAS/COLORADO BORDER. UPSLOPE 
SURFACE REGIME WILL BE IN PLACE AND ANOTHER SHORTWAVE ROTATES AROUND 
DESERT SOUTHWEST ANTICYCLONE. CAP LOOKS STRONGER THAN ON 
THURSDAY...AND GIVEN THIS UNCERTAINTY WILL LEAVE DRY FOR NOW. AS 
UPSLOPE FLOW CONTINUES INTO SATURDAY 700 MB MOISTURE INCREASES 
FURTHER. UPPER RIDGE APPEARS TO RETREAT SOMEWHAT...BUT AGAIN 
QUESTION OVER CAP STRENGTH WITH 700 MB TEMPERATURES FORECAST TO BE 
14 TO 16C. WILL WITHHOLD MENTION OF THUNDER FOR NOW. TEMPERATURE 
TRENDS LOOK ON TRACK WITH ABOVE NORMAL EXPECTED THROUGHOUT THE 
PERIOD BASED ON 850 TEMPERATURE FORECASTS. 

.GLD...NONE.

$$

JDK