Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 KLBF 291120
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
520 AM CST MON DEC 29 2014

.SYNOPSIS...
ISSUED AT 325 AM CST MON DEC 29 2014

THE 08Z MSL DATA SHOWED A WEAK QUASI-STATIONARY FRONT ACROSS KANSAS
AND EASTERN COLORADO. IN THE DISTANCE...THERE WAS A STRONG 1056MB
HIGH PRESSURE ALONG THE YUKON-BRITISH COLUMBIA BORDER. THE COLDEST
TEMPERATURES ARE SOUTH OF THE CENTER OF THE AIR MASS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CST MON DEC 29 2014

THE FIRST CONCERN IS THE LIKELIHOOD OF A LARGE AREA OF LIGHT SNOW
MAKING ITS WAY TO CENTRAL AND SOUTHWEST NEBRASKA AND ENDING IN THE
NORTH THIS EVENING. SYSTEM RELATIVE ISENTROPIC LIFT CONTINUES IN THE
270-285K LAYER OVER THE WEAK FRONT IN KANSAS AND EASTERN COLORADO
WITH FRONTOGENETIC ENHANCEMENT IN THE 275-280K LAYER. WITH ALL OF
THE SATURATED AIR IN THE DENDRITIC FORMATION ZONE...HIGH SNOW TO
LIQUID RATIOS WILL RESULT. AT THE TIME WE ARE USING 16-20 TO
1...THOUGH THEY MAY EXCEED 25 TO 1 AS THEY DID WITH THE LAST SYSTEM.
WITH SPECIFIC HUMIDITY IN THE LIFT LAYER OF 0.5-2.0G/KG...AVAILABLE
MOISTURE IS NOT HIGH. IN FACT...PRECIPITABLE WATER VALUES ARE 0.15
INCH OR LOWER. WITH THE LOW WATER CONTENT... WIND GUSTING TO 25 MPH
WILL CAUSE DRIFTING AND LOCALIZED BLOWING SNOW.

DENSE ARCTIC AIR...NOW IN NORTHWEST CANADA...IS EXPECTED TO REACH
THE HIGH PLAINS OF MONTANA TONIGHT. THE WIND TONIGHT WILL BE 15 TO
20 MPH AND TEMPERATURE WILL REACH LOWS OF -5F TO -15F CREATING
APPARENT TEMPERATURES OF -20F TO JUST ABOVE -30F.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CST MON DEC 29 2014

THE EXTENDED PERIOD STARTS OUT WITH LINGERING LIGHT SNOW IN
SOUTHWEST NEBRASKA AND FRIGID COLD TEMPERATURES AS THE CORE OF THE
ARCTIC AIR MOVES INTO THE CENTRAL PLAINS ON TUESDAY. CLOUD
COVER...H85 TEMPS AROUND -18C...AND SNOW PACK WILL KEEP TEMPERATURES
WELL BELOW NORMAL...STRUGGLING TO GET INTO THE SINGLE DIGITS FOR
MUCH OF THE AREA. AS FOR TUESDAY NIGHT..STILL EXPECTING OUR COLDEST
NIGHT SO FAR THIS WINTER AND DANGEROUSLY COLD WIND CHILL LEVELS NEAR
OR BELOW -30 FOR MUCH OF THE AREA INTO WEDNESDAY MORNING.

A WARMING TREND IN THE GUIDANCE CONTINUES FOR WEDNESDAY THROUGH THE
END OF THE WEEK. AN UPPER LEVEL LOW CUTS OFF IN THE DESERT
SOUTHWEST...RESULTING IN SOUTHWEST FLOW AND H85 TEMPERATURES WARMING
TO ALMOST 4C BY FRIDAY. SNOW PACK WILL LIKELY KEEP SURFACE HIGH
TEMPERATURES BELOW FREEZING...BUT THE AIR WILL FEEL APPRECIABLY
WARMER THAN THE FRIGID TEMPS TO START THE WEEK.

THE GFS AT DAY 5 AND BEYOND HAS TRENDED TOWARD EC WITH A LESS
AMPLIFIED PATTERN...AND MORE OF A BROAD TROUGH OVER THE EASTERN TWO
THIRDS OF THE CONUS AND PUSHES THE BULK OF THE REALLY COLD ARCTIC
OFF TO OUR EAST. HOWEVER...BELOW NORMAL TEMPERATURES ARE STILL
EXPECTED. BOTH MODELS SLOWLY BRING THE CLOSED LOW OUT OF THE
SOUTHWEST AND INTO THE SOUTHERN PLAINS BY THE WEEKEND...BUT KEEP
PRECIP CHANCES SOUTH OF OUR AREA.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 520 AM CST MON DEC 29 2014

WIDESPREAD SNOW IN NORTHERN NEBRASKA IS EXPECTED TO CONTINUE INTO
THE AFTERNOON. SNOW WILL ALSO BE SPREADING INTO CENTRAL AND
SOUTHWEST NEBRASKA THIS MORNING AND EARLY AFTERNOON. IT IS
REASONABLE TO EXPECT THAT VISIBILITY WITH THE LIGHT SNOW WILL BE
OCCASIONALLY BELOW 3SM AND COULD BE BELOW 1SM.

&&

.HYDROLOGY...
ISSUED AT 325 AM CST MON DEC 29 2014

ICE JAMS ON AREA RIVERS AND STREAMS WILL CONTINUE TODAY AS ARCTIC
AIR SETTLES INTO THE PLAINS. THE NORTH PLATTE AT THE INLET TO LAKE
MCCONAUGHY NEAR LEWELLEN HAS ALREADY RISEN ABOVE THE FLOOD STAGE OF
7.5 FEET. AN ICE JAM HAS FORMED ON THE SOUTH PLATTE DOWNSTREAM OF
NORTH PLATTE AND IS CAUSING BANK FULL CONDITIONS. WITH PERSISTENT
COLD...OTHER STREAMS ARE LIKELY TO HAVE ICE JAMS. FLOODING...IF
ANY...IS LIKELY TO BE MINOR WITH WATER COMING OUT INTO PASTURES AND
OTHER LOW AREAS ALONG THE RIVERS.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM MIDNIGHT CST /11 PM MST/ TONIGHT TO 1
PM CST /NOON MST/ TUESDAY FOR NEZ056>059-069>071.

WIND CHILL ADVISORY FROM 6 PM CST /5 PM MST/ THIS EVENING TO 1
PM CST /NOON MST/ TUESDAY FOR NEZ004>010-022>029-035>038-094.

&&

$$

SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...MARTIN
AVIATION...SPRINGER
HYDROLOGY...SPRINGER





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