HAMweather.com Area Forecast Discussion for County Warning Area GID

Thu, 16 Feb 2012 07:41:39 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1140 PM CST WED FEB 15 2012

.AVIATION...06Z KGRI TAF...NORTHWESTERLY WINDS LESS THAN 10 KTS
WILL SLOWLY BACK OVER THE NEXT 24 HOURS AND BECOME MORE
SOUTHWESTERLY AS AN AREA OF SURFACE HIGH PRESSURE TRANSITIONS FROM
THE HIGH PLAINS ACROSS THE STATE OF KANSAS. GENERALLY CLOUD FREE
SKIES ARE EXPECTED OVERNIGHT...WITH A FEW MID LEVEL CLOUDS
INDICATED IN MODEL DATA AS WELL AS UPSTREAM IN SATELLITE DATA.
MORE SIMPLY PUT...VFR CONDITIONS EXPECTED TO DOMINATED FOR THE
NEXT 24 HOURS WITH GENERALLY LIGHT WINDS OF 10 KTS OR LESS. 

.PREV DISCUSSION... /ISSUED 348 PM CST WED FEB 15 2012/

SHORT TERM...TONIGHT AND THURSDAY...THE SHORT TERM FORECAST LOOKS 
STRAIGHT FORWARD. THE MID-LEVEL SHORTWAVE TROUGH AXIS HAS MOVED EAST 
OF THE CWA. THE ELEVATED FRONT WHICH CONVECTION EARLIER FIRED ON HAS 
WITHERED ON THE VINE AS THE AFTERNOON PROGRESSES WITH INCREASED 
SUBSIDENCE OCCURRING ON THE BACKSIDE OF THE SHORTWAVE TROUGH. 
AFTERNOON HEATING MAY SPARK A SHOWER OR TWO IN OUR FAR EAST...BUT 
FOR THE MOST PART WE SHOULD BE DONE WITH PRECIPITATION. MOST IF NOT 
ALL MODEL SOLUTIONS INDICATE A DRY FORECAST THIS EVENING INTO 
THURSDAY. AS THE SURFACE HIGH MOVES EAST THROUGH THE CENTRAL PLAINS 
TONIGHT...WIND SPEEDS SHOULD DIMINISH. RETURN FLOW ON THURSDAY FROM 
THE SOUTHWEST WILL HELP BOOST TEMPERATURES INTO THE 40S. USED THE 
HELP OF VERIFICATION DATA FROM BOIVERIFY FOR TEMPERATURES AND 
DEWPOINTS.

LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. PRIMARY FORECAST
CONCERN LIES WITH TEMPERATURES AND PRECIPITATION CHANCES IN THE 
LATE WEEKEND/EARLY NEXT WEEK PERIOD.

THURSDAY NIGHT THROUGH SATURDAY. MODELS IN GOOD AGREEMENT AT THE 
START OF THE LONG TERM PERIOD AND THE FORECAST REMAINS 
DRY...THURSDAY EVENING SHOWS GENERALLY ZONAL FLOW IN THE UPPER 
LEVELS ACROSS THE REGION...WITH A LOW PRESSURE SYSTEM SPINNING OVER 
THE BAJA OF CAL AND A TROUGH AXIS SWINGING SOUTH OUT OF CANADA AND 
INTO THE DAKOTAS. DURING THE OVERNIGHT HOURS...THIS TROUGH AXIS 
CONTINUES TO SHIFT SOUTH THROUGH THE PLAINS...AND EVEN BY 12Z 
FRIDAY...STILL REMAINS JUST OFF TO THE NORTH OF THE CWA. AS WE GET 
INTO THE DAYTIME HOURS FRIDAY/FRIDAY NIGHT...THIS TROUGH FINALLY 
PUSHES THROUGH THE CWA...AND AS IT PUSHES SOUTH BECOMES MORE PHASED 
IN WITH THE SOUTHERN CONUS ENERGY WHICH HAD BEEN THAT PREVIOUSLY 
MENTIONED CLOSED LOW OVER THE BAJA.  WHILE MODELS SHOW PRECIPITATION 
TRYING TO BUILD NORTH OUT AHEAD OF THAT SYSTEM...THIS NORTHERN 
STREAM TROUGH HELPS TO KEEP THINGS PUSHED TO THE SOUTH OF THE CWA.  
WITH DRY CONDITIONS CONTINUING...THE MAIN IMPACT FELT FROM THIS IS 
WITH THE PASSAGE OF A SURFACE COOL FRONT...WITH TIMING BETWEEN 
MODELS GENERALLY SHOWING IT CLEARING THE CWA BY LATE FRIDAY 
AFTERNOON.  NOT A REAL STRONG PUSH BEHIND IT...SO NOT EXPECTING A 
SIGNIFICANT INCREASE IN THE NORTHWESTERLY WINDS WHICH DEVELOP...AND 
WITH THE COOLER AIR LAGGING BEHIND...SHOULDNT HAVE MUCH OF A 
NEGATIVE IMPACT ON FRIDAY HIGHS.  FORECAST HIGHS CURRENTLY SITTING 
IN THE LOWER/MID 40S FOR MOST OF THE CWA...WHICH WILL ALSO SEE A 
DOWNSLOPING COMPONENT WITH THOSE W/NWRLY WINDS.  EXPECTING COOLER 
TEMPERATURES...BUT STILL DRY CONDITIONS...INTO SATURDAY. UPPER LEVEL 
FLOW LOOKS TO BECOME MORE NORTHWESTERLY IN THE WAKE OF THE TROUGH 
AXIS...WITH SURFACE HIGH PRESSURE SETTLING IN ACROSS THE REGION BY 
12Z SATURDAY.  LIGHTER WINDS AND MOSTLY CLEAR SKIES IS EXPECTED TO 
BRING OVERNIGHT LOWS GENERALLY IN THE MID TEENS TO LOWER 20S...WITH 
HIGHS ON SATURDAY RANGING FROM THE MID/UPPER 30S IN THE NORTHEAST  
TO LOWER 40S FURTHER SOUTHWEST. 

SATURDAY NIGHT AND INTO SUNDAY...THE DRY FORECAST CONTINUES ACROSS 
THE CWA...WITH MODELS NOT IN TOO BAD OF AGREEMENT.  THE UPPER LEVEL 
PATTERN SATURDAY EVENING/NIGHT TRANSITIONS FROM NORTHWESTERLY FLOW 
TO MORE ZONAL FLOW AS A SHORTWAVE RIDGE AXIS SLIDE EAST OUT OF THE 
ROCKIES...A RESULT OF A TROUGH DRAPED THROUGH THE GREAT LAKES AND 
MIDWEST...AND ANOTHER SHIFTING INLAND FROM THE WEST COAST.  SURFACE 
HIGH PRESSURE AXIS STARTS THE EVENING AFFECTING THE EASTERN THIRD OF 
THE CWA...THE GRADUALLY SLIDES OFF THE EAST OVERNIGHT...ALLOWING FOR 
A RETURN OF SOUTHERLY WINDS.  THIS UPPER LEVEL RIDGE LOOKS TO BE THE 
DOMINANT FEATURE ACROSS THE CENTRAL PLAINS DURING THE DAY ON 
SUNDAY...WITH GOOD MODEL AGREEMENT SHOWING THE AXIS DRAPED RIGHT 
THROUGH THE CWA AT MIDDAY. BUMPED UP HIGH TEMPERATURES A FEW DEGREES 
FOR SUNDAY /MAINLY ACROSS SC NEB/...WITH SOUTHERLY WINDS IN PLACE 
AND WARMER TEMPS BUILDING IN FROM THE WEST...FORECAST HIGHS ARE IN 
THE MID/UPPER 40S. 

SUNDAY NIGHT THROUGH MONDAY NIGHT...POSSIBILITY FOR PRECIPITATION 
RETURNS TO THE FORECAST...BUT WILL STATE THAT CONFIDENCE IS ON THE 
LOW SIDE.  NOT THAT AGREEMENT WITH PREVIOUS RUNS WERE GREAT...BUT 
THE 12Z RUN OF THE GFS/EC SHOWING PLENTY OF VARIATION...WITH EACH 
OTHER AND EVEN FROM RUN TO RUN.  THE GFS HAS VERY LITTLE GOING ON 
ACROSS THE CWA...BETWEEN WITH A CLOSED LOW WELL TO THE SOUTH AND A 
TROUGH AXIS SWINGING THROUGH THE NORTHERN PLAINS AND INTO THE GREAT 
LAKES. THE 00Z EC BROUGHT A CLOSED LOW RIGHT OVER THE CWA...BUT THE 
12Z RUN HAS MADE A NOTABLE SHIFT NORTH...AND WHILE STILL SHOWING AN 
IMPACT...THE MAIN FOCUS IS TO THE NORTH. POPS REMAIN TRENDED MORE 
TOWARD THE EC...AND ADJUSTED THE HIGHER POPS TO THE NORTHERN 
PORTIONS OF THE CWA. AT THIS POINT THE MAIN TIMING WOULD BE DURING 
THE SUNDAY NIGHT/MONDAY DAY TIME FRAME...WITH TAPERING POPS MONDAY 
EVENING. NEITHER MODEL HAS A SIGNIFICANTLY COLDER AIRMASS 
ACCOMPANYING THE FRONTAL PASSAGE ON MONDAY...BUT A RA/SN MIX WILL BE 
POSSIBLE...ESP IN THE NIGHTTIME/MORNING HOURS. 

DRY FORECAST RETURNS FOR TUESDAY IN THE WAKE OF THIS LATEST 
SYSTEM...BUT MODELS SHOWING IT TO BE A SHORT BREAK...AS ANOTHER 
SHORTWAVE UPPER LEVEL DISTURBANCE MOVES INTO THE REGION. GENERAL 
TREND IS TO KEEP POPS CONFINED TO THE NORTHERN HALF OF THE CWA. 
AFTER SEEING A DROP IN HIGHS INTO THE UPPER 30S/MID 40S ON MONDAY 
WITH INCREASED CLOUD COVER/PRECIP CHANCES...TEMPS LOOK TO REBOUND 
TUESDAY AND WED INTO THE LOWER/MID 40S TUES AND MID/UPPER 40S WED. 
HIGHS ON WED MAY END UP BEING TOO HIGH IF MODELS CONTINUE TO KEEP 
THE PRECIPITATION TREND AROUND. 

.GID WATCHES/WARNINGS/ADVISORIES...

NE...NONE.
KS...NONE.