FXUS63 KGID 111136

AFDGID



AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HASTINGS NE

536 AM CST THU MAR 11 2010



.AVIATION...12Z TAF. PRECIPITATION CONTINUES TO WRAP AROUND AN

AREA OF LOW PRESSURE LOCATED ACROSS NORTHWEST MISSOURI. THE LOW

WILL MOVE NORTH TODAY INTO WESTERN IOWA...AND THEN WOBBLE AROUND

IN THAT GENERAL AREA TONIGHT. KUEX-WSR-88D SHOWS KGRI IS GENERALLY

BETWEEN PRECIPITATION AREAS EARLY THIS MORNING...BUT MOST SHORT

TERM FORECAST MODELS GENERALLY AGREE THAT PRECIPITATION SHOULD

START AT KGRI BY MID MORNING. WILL START THE SNOW IN THE TAF

TOWARDS 15Z IN A TEMPO GROUP...AND THEN CARRY SNOW WITH

VISIBILITIES AROUND 2SM DURING THE AFTERNOON. ONCE THE SNOW BEGINS

IT SHOULD CONTINUE OFF AND ON THROUGH TONIGHT. CEILINGS ARE

CURRENTLY AROUND 1500 FT AT KGRI...AND THINK THOSE MAY FALL A

LITTLE...BUT NOT CONFIDENT IN THEM FALLING BELOW 1KFT. WILL DROP

CEILINGS TO AROUND 1KFT DURING THE SNOW FOR NOW...AND ADJUST THEM

LOWER IF THAT TREND BECOMES MORE APPARENT. WINDS WILL ALSO BE ON

THE INCREASE THIS MORNING...AND SHOULD BECOME GUSTY BY 14 OR 15Z.



&&



.PREV DISCUSSION... /ISSUED 349 AM CST THU MAR 11 2010/ 



DISCUSSION...PRIMARY FORECAST CONCERN THROUGH THE NEXT FEW DAYS

CENTER UPON THE TRACK OF A MID LEVEL LOW ACROSS THE CENTRAL

PLAINS. EVENING UPPER AIR ANALYSIS INDICATE THE MID LEVEL LOW

LOCATED OVER EASTERN KANSAS...MOVING NORTHEAST INTO THE MISSOURI

VALLEY. WIDE SPREAD CONVECTION IS NOTED EXTENDING ACROSS MUCH OF

THE MISSISSIPPI VALLEY THIS EVENING...WITH STRATIFORM RAIN PUSHING

INTO IOWA AND SOUTHEASTERN NEBRASKA ALONG AN AREA OF WAA AND

ENHANCED OMEGA. SOME OF THE PRECIPITATION ON THE BACK SIDE OF THIS

SYSTEM IS CLIPPING EXTREME SOUTHEASTERN PORTIONS OF OUR CWA EARLY

THIS MORNING...WITH A BAND OF LIGHT RAIN NOTED ON RADAR EXTENDING

FROM BELOIT...NORTHWARD TO YORK.



MODEL CONSENSUS CONTINUES TO POINT TOWARDS A BAND OF HEAVY

PRECIPITATION SETTING UP SOMEWHERE IN THE REGION...ON THE BACK SIDE

OF THE LOW IN AN AREA OF DEFORMATION. BIGGEST QUESTION IS STILL

THE EXACT POSITION OF THIS HEAVIER PRECIPITATION. THE GFS REMAINS

THE WORSE CASE SCENARIO FOR PORTIONS OF OUR CWA...WITH THE 00Z

OPERATIONAL GFS DUMPING ALMOST A HALF INCH OF LIQUID PRECIPITATION

ACROSS OUR EAST TODAY AND ANOTHER NEAR HALF INCH TONIGHT. OTHER

MODELS INCLUDING THE NAM...GEM...RUC AND EC CONTINUE PUSHING THE

HEAVIER PRECIPITATION EASTWARD...KEEPING THE BULK OF THE HEAVY

PRECIPITATION TO THE EAST OF OUR CWA. GIVEN THE UNCERTAINTY OF

WHERE EXACTLY THE HEAVY PRECIPITATION WILL SET UP...WILL FORECAST

WITH A BLEND OF MODEL GUIDANCE. WHAT MODEL CONSENSUS THERE IS

CERTAINLY SUGGEST NORTHEASTERN AND EASTERN PORTIONS OF OUR CWA

STAND THE BEST CHANCE OF SEEING HEAVY PRECIPITATION AND HAVE

FORECAST THE HEAVIEST PRECIPITATION AMOUNTS ACROSS THESE

LOCATIONS...THEN TAPERING OFF PRECIPITATION AS ONE MOVES TO THE

SOUTHWEST. SNOW AMOUNTS THEN BECOME PROBLEMATIC AS FORECAST LOW

LEVEL TEMPERATURES SUGGEST EITHER A RAIN AND SNOW MIX FOR A WET

SNOW. HAVE CUT SNOW RATIOS DOWN CLOSER TO 8:1 TO ACCOUNT FOR

THIS...WHICH SHOULD YIELD SNOWFALL ACCUMULATIONS ON THE ORDER OF

1-2 INCHES ACROSS OUR EAST TODAY...AND PERHAPS ANOTHER 1-2 INCHES

TONIGHT...ALTHOUGH THIS STILL MAY BE ON THE HIGH SIDE FOR BOTH

PERIODS. SNOWFALL AMOUNTS OF LESS THAN ONE INCH ARE ANTICIPATED

FARTHER SOUTHWEST. THE WINDS ARE THE FINAL COMPONENT IN AN ALREADY

DIFFICULT AND UNCERTAIN FORECAST. NORTHWESTERLY WINDS SHOULD

INTENSIFY ACROSS NORTHERN PORTIONS OF OUR CWA AS PRESSURE RISES

COMMENCE LATER TODAY. STRONG NORTHWESTERLY WINDS WILL THEN PERSIST

THROUGH TONIGHT AND INTO THE DAY FRIDAY...WITH THE STRONGEST WINDS

EXPECTED OVERNIGHT TONIGHT. SHOULD THESE WINDS TAKE PLACE IN A

BAND OF HEAVIER SNOW...VISIBILITY RESTRICTIONS WILL BE AN ISSUE

AND A WINTER WEATHER ADVISORY WILL CERTAINLY BE WARRANTED. GIVEN

THE UNCERTAINTY OF THE HEAVY PRECIPITATION POSITION...AND WHETHER

OR NOT SNOW WILL BE HEAVY ENOUGH TO YIELD SIGNIFICANT VISIBILITY

RESTRICTIONS THUS REQUIRING A WINTER WEATHER ADVISORY...WILL HOLD

OFF ON ANY HEADLINES FOR THE TIME BEING. NEEDLESS TO

SAY...CONDITIONS WILL NEED TO BE CLOSELY MONITORED THROUGH THE DAY

TODAY AND INTO TONIGHT FOR THE POSSIBLE ISSUANCE OF

HEADLINES...WHETHER THAT BE A POSSIBLE WINTER WEATHER ADVISORY

LATER TODAY...OR A POSSIBLE WIND ADVISORY TONIGHT. CHANCES FOR

SNOW SHOULD TAPER OFF BY LATE FRIDAY...LEADING THE WAY TO QUIETER

WEATHER THROUGH THE REMAINDER OF THE FORECAST PERIOD.



PREV DISCUSSION... /ISSUED 1123 PM CST WED MAR 10 2010/ 



AVIATION...06Z TAF. INTERESTING FORECAST OVER THE NEXT 24 TO 36

HOURS DUE TO SNOW CHANCES AT KGRI. KUEX WSR- 88D LATE THIS EVENING

SHOWS BANDS OF PRECIPITATION ROTATING AROUND AN AREA OF LOW

PRESSURE ACROSS EASTERN KANSAS. THE 00Z NAM AND GFS STILL HAVE

DIFFERING IDEAS ON HOW THIS SYSTEM WILL PROGRESS WITH THE NAM

GENERALLY KEEPING THE MORE STEADY PRECIPITATION EAST OF KGRI MUCH

OF THE DAY...WHILE THE GFS BRINGS IT IN FASTER. GENERALLY DECIDED

TO FOLLOW A BIT CLOSER TO THE GFS SINCE IT APPEARS TO BE DOING A

BIT BETTER WITH THE ONGOING PRECIPITATION BAND CURRENTLY EAST OF

KGRI. THIS WILL BRING A CHANCE OF RAIN/SNOW TO KGRI TOWARDS

11Z...AND THEN A MORE STEADY SNOW BY MID TO LATE MORNING. ITS

ENTIRELY POSSIBLE THAT A LITTLE RAIN MAY AT TIMES MIX IN THE WITH

THE SNOW DEPENDING ON WHAT THE BOUNDARY LAYER TEMPERATURES DO DURING

THE AFTERNOON...BUT GENERALLY WENT WITH MORE SNOW THAN RAIN DUE TO

THE THERMAL PROFILE IN THE GFS. THE SNOW SHOULD GRADUALLY DIMINISH

DURING THE LATE AFTERNOON/EVENING...BUT AGAIN IF THE NAM IS

CORRECT THE TIMING OF THIS COULD BE OFF. WINDS WILL BE ANOTHER

ISSUE SINCE THEY SHOULD INCREASE FROM THE NORTHWEST THROUGH THE

MORNING. THEY WILL INCREASE EVEN MORE DURING THE AFTERNOON...AND

COULD AT TIMES GUST TO 30-35 KTS.



&&



.GID WATCHES/WARNINGS/ADVISORIES...

NE...NONE.

KS...NONE.

&&



$$