Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KOAX 311145
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
545 AM CST SAT JAN 31 2015

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 345 AM CST SAT JAN 31 2015

CHALLENGING FORECAST OVER THE NEXT 6 TO 42 HOURS AS A POTENT WINTER
STORM AFFECTS THE AREA WITH PRECIPITATION TYPE...SNOW AMOUNTS AND
BLOWING SNOW ON THE BACKSIDE OF THE SYSTEM ALL CONCERNS. QPF
AMOUNTS ARE SIGNIFICANT AND THIS LEADS TO MORE SIGNIFICANT SNOW
AMOUNTS.

AT H3...A 120KT NORTHWEST TO SOUTHEAST JET STRETCHED FROM THE GREAT
LAKES TO THE SOUTHEAST.   A 100KT JET WAS OFF THE COAST OF BAJA.  AT
H5 A LARGE AREA OF LOW PRESSURE WAS OVER THE SOUTHWEST U.S.  40M
HEIGHT FALL WERE OVER THE WESTERN HIGH PLAINS WITH 60-80M HEIGHT
FALLS FROM NEW MEXICO INTO MEXICO.  AT H7 THERE WAS A WEAK LOW OVER
NORTHEAST COLORADO...WITH THE MAIN LOW OVER THE SOUTHWEST U.S. AT
OAX...OUR H5 TEMPERATURES WAS +5...HOWEVER THERE WAS A POCKET OF
COLDER TEMPERATURES FROM WESTERN KANSAS INTO THE TEXAS PANHANDLE.
AS NOTED ON THE EVENING SHIFT...THIS SYSTEM HAS A LOT OF MOISTURE
WITH IT.  9+ DEG H85 DEWPOINTS WERE OVER SOUTHERN ARIZONA.

WATER VAPOR SATELLITE IMAGERY/LIGHTNING SHOWS A LOT OF MID LEVEL MOISTURE
OVER THE SOUTHWEST U.S. WITH LIGHTNING OVER MEXICO AHEAD OF THE H5
LOW. LEAD SHORTWAVE ENERGY IS TRACKING ACROSS NEBRASKA WITH SOME
COUPLED JET SUPPORT. A STRENGTHENING SOUTHWEST FLOW AHEAD OF THE
STORM SYSTEM IS PULLING MOISTURE NORTHEAST ACROSS KANSAS INTO
NEBRASKA. THE LATEST WSR-88D RADAR MOSAIC HAS THE LEADING EDGE OF
THE LIGHT RAIN TO BEATRICE WITH DEWPOINTS IN THE LOWER 30S.  THERE HAS
BEEN SOME LIGHT SNOW FOR PARTS OF WESTERN KANSAS INTO SOUTHWEST
NEBRASKA.

OVERALL THERE IS GOOD AGREEMENT IN THE TRACK AND STRENGTH OF THE
STORM. THE MAIN DIFFERENCES ARE ASSOCIATED WITH THE PRECIPITATION
TYPE.

DURING THE DAY...THETA-E ADVECTION CONTINUES AS THE MID
TROPOSPHERIC TROF OVER THE ROCKIES MOVES INTO THE PLAINS. UPWARD
VERTICAL MOTION WITH THE SHORTWAVE TROF AND CONTINUED UPPER LEVEL
SUPPORT WILL ALLOW THE PRECIPITATION TO SPREAD NORTHEAST ACROSS
THE FORECAST AREA. FORECAST SOUNDINGS POINT TO A MIX OF SNOW AND RAIN
AND SNOW POSSIBLE DURING THE DAY WITH MAINLY RAIN NEAR THE KANSAS
BORDER AND THE MIX CHANGING TO ALL SNOW IN THE NORTHEAST PART OF
THE FORECAST AREA. TEMPERATURES IN THE 30S WILL ALSO LIMIT SNOW
ACCUMULATIONS ON ROADS. THE QUESTION WILL BE IF THE COMBINATION OF
DYNAMIC LIFT AND COOLING WILL CHANGE THE PRECIPITATION TO ALL SNOW
QUICKER AS THIS WOULD INCREASE SNOW AMOUNTS. AT OMA...THE NAM HAS
THE MIX THROUGH 22Z...WHILE THE GFS HOLDS ON TO THE MIX THROUGH
03-06Z. THROUGH 00Z...THE QPF AMOUNTS ARE GENERALLY A TENTH OF AN
INCH ACROSS NORTHEAST NEBRASKA INTO WEST CENTRAL IOWA WITH A TENTH
OF AN INCH TO A QUARTER OF AN INCH FROM SOUTHEAST NEBRASKA INTO
SOUTHWEST IOWA. DURING THE DAY...THINK MOST LOCATIONS COULD SEE A
TRACE TO 1 INCH OF SNOW...HOWEVER SOME SPOTS COULD PICK UP AND
INCH OR TWO.

THE H85 BOUNDARY LIFTS NORTH DURING THE DAY...AND BY 00Z THE
CIRCULATION ID NEAR COLUMBUS WITH RAIN CHANGING TO ALL SNOW IN
NORTHEAST NEBRASKA. THROUGH 06Z...THE SURFACE LOW IS OVER
NORTHEAST KANSAS...WITH THE H85 CIRCULATION NEAR TEKAMAH. DURING
THE EVENING EXPECT THE RAIN TO CHANGE TO ALL SNOW FROM NORTHWEST
TO SOUTHEAST...WITH FAVORABLE DENDRITIC TEMPERATURES INCREASING
THE SNOW TO LIQUID RATIOS. BY 12Z...THE SURFACE LOW IS NEAR KANSAS
CITY WITH NORTHWEST WINDS INCREASING ACROSS THE FORECAST AREA AND
2 TO 6 INCHES OF SNOW POSSIBLE...WITH LIGHTER AMOUNTS TOWARD
FAIRBURY AND HIGHER AMOUNTS TOWARD HARLAN. ADDITIONAL LIGHT SNOW
SHOULD FALL SUNDAY WITH SOME 1 TO 3 INCH AMOUNTS TAPERING TO
FLURRIES. MUCH STRONGER WINDS ARE FORECAST FOR SUNDAY...THUS
BLOWING SNOW WILL BE AN ISSUE.

THIS IS A LONG DURATION EVENT. DUE TO THE SNOW AND WINDS...ISSUED
A WINTER STORM WARNING FOR OUR IOWA COUNTIES SAVE FOR MILLS AND
FREMONT. OMAHA...THURSTON...BURT...AND CUMING COUNTIES AS WELL AS
OTHERS MAY ALSO NEED CONSIDERATION SUNDAY WITH THE STRENGTHENING
WINDS...HOWEVER AT THIS TIME PUT THE REST OF THE FORECAST AREA IN
AN ADVISORY. STARTED THE HEADLINES AT 6PM DUE TO THE LIMITATIONS
IN AMOUNTS PRIOR TO THAT DISCUSSED ABOVE. THE STRONG WINDS MAY BE
ENOUGH TO PRODUCE BLIZZARD CONDITIONS...SO THIS WILL NEED TO BE
WATCHED LATE TONIGHT AND SUNDAY MORNING. THE BULK OF THE SNOW
SHOULD BE ENDING BY SUNDAY EVENING.

FOR THE ENTIRE EVENT QPF IS FORECAST TO RANGE FROM 0.4-1.1 INCHES
WITH THE LIGHTER AMOUNTS IN THE NORTHWEST AND THE HEAVIER AMOUNTS
IN THE SOUTHEAST. TOTAL SNOW AMOUNTS COULD RANGE FROM 3 TO 9
INCHES WITH LIGHTER AMOUNTS NEAR THE KANSAS BORDER...3 TO 7 INCHES
ACROSS THE REST OF NEBRASKA AND 5 TO 9 INCHES FOR WESTERN IOWA.
THESE NUMBERS WILL VARY DEPENDING ON HOW QUICKLY THE RAIN CHANGES
TO SNOW AND IF ANY PERSISTENT BANDS DEVELOP.

HIGH TEMPERATURES TODAY WILL BE IN THE 30S...LOWS TONIGHT WILL
DROP BACK INTO THE TEENS AND 20S. STEADY/FALLING TEMPERATURES ARE
FORECAST FOR SUNDAY WITH LOWS IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO MONDAY MORNING.

THERE IS SOME MODERATION FOR MONDAY WITH HIGHS IN THE 20S AND 30S
AND THERE MAY BE A LITTLE LIGHT SNOW AS THE WARMER AIR TRIES TO
WORK BACK IN TO THE REGION.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 AM CST SAT JAN 31 2015

NORTHWEST FLOW WILL DOMINATE THE LONG TERM PERIOD. SEVERAL IMPULSES
ROLLING THROUGH THE FLOW WILL BRING TRANSIENT PRECIPITATION
CHANCES...BUT MODEL INCONSISTENCY WILL MAKE IT DIFFICULT TO NAIL
DOWN TIMING OF THOSE CHANCES. IT LOOKS LIKE THE BEST CONSISTENCY
BETWEEN GFS/ECMWF COMES TUESDAY INTO WEDNESDAY WHEN A STRONGER
IMPULSE ENTERS THE REGION. AHEAD OF THIS WAVE...SOUTHERLY FLOW
SHOULD PUSH TEMPERATURES TO OR ABOVE NORMAL...BUT WITH SNOWCOVER
FROM THIS WEEKEND STORM...WILL LIKELY HOLD TUESDAY HIGHS TO THE 30S.
IF PRECIPITATION BEGINS TUESDAY AFTERNOON WE COULD SEE RAIN OR A
MIX...BUT AM EXPECTING PRECIP TO START TUESDAY EVENING WHEN
TEMPERATURES WILL SUPPORT SNOW. THIS SNOW LINGERS INTO
WEDNESDAY...BUT AMOUNTS SHOULD BE MINIMAL GIVEN FAST-MOVING SYSTEM.
MUCH COLDER ON WEDNESDAY AS WELL WITH 850 TEMPERATURES DROPPING INTO
THE 10 TO 15C BELOW RANGE. HIGHS THEN WILL ONLY GAIN A FEW DEGREES
FROM MORNING HIGHS. THEN A COLD START THURSDAY IN THE SINGLE DIGITS
WILL BE REPLACED BY A SLIGHT WARMING TREND AS SOUTHERLY FLOW
RETURNS. EXPECT HIGHS IN THE 20S THURSDAY AND 30S FRIDAY.

&&

.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 540 AM CST SAT JAN 31 2015

DETERIORATING CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. MVFR
CIGS/VSBYS WITH RAIN/FOG SHOULD OVERSPREAD ALL EASTERN NEBRASKA
TAF SITES BY 18Z. A GRADUAL TREND TOWARD A MIXTURE OF RAIN AND
SNOW...AND AT TIMES ALL SNOW...WILL OCCUR BETWEEN 18Z AND 02Z
BEFORE CHANGING TO ALL SNOW AT ALL SITES BETWEEN 02Z AND 06Z.
CIGS AND VSBYS WILL BE SOLIDLY INTO THE IFR CATEGORY AFTER 06Z.
OCCASIONAL LIFR OR VLIFR CONDITIONS ARE LIKELY AS WE HEAD TOWARD
12Z...ESPECIALLY WHEN NORTH WINDS AT 15 TO 25KT KICK IN LATE IN
THE TAF PERIOD. SNOW AND INCREASING WINDS ARE FORECAST BEYOND 12Z
SUNDAY...WITH BLOWING SNOW LIKELY PRODUCING BRIEF BLIZZARD
CONDITIONS AT KOFK AND KOMA TAF SITES MUCH OF SUNDAY MORNING INTO
THE EARLY AFTERNOON.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
     SUNDAY FOR NEZ065>068-078-088>093.

     WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
     SUNDAY FOR NEZ011-012-015>018-030>034-042>045-050>053.

IA...WINTER STORM WARNING FROM 6 PM THIS EVENING TO 9 PM CST SUNDAY
     FOR IAZ043-055-056-069-080-091.

     WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
     SUNDAY FOR IAZ079-090.

&&

$$

SHORT TERM...ZAPOTOCNY
LONG TERM...DERGAN
AVIATION...DERGAN


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.