Area Forecast Discussion
Issued by NWS North Platte, NE

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000
FXUS63 KLBF 061130
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
630 AM CDT FRI MAY 6 2016

.SYNOPSIS...
ISSUED AT 344 AM CDT FRI MAY 6 2016

A HIGHLY AMPLIFIED H5 PATTERN CONTINUES ACROSS THE CONUS
TONIGHT. UA ANALYSIS FROM EARLIER THIS EVENING HAD A RIDGE OF HIGH
PRESSURE EXTENDING FROM EASTERN NEW MEXICO...NORTH TO SRN
SASKATCHEWAN. CLOSED LOWS WERE PRESENT ON EITHER SIDE OF THE RIDGE.
THE FIRST LOW WAS LOCATED OVER THE CAROLINAS...WHILE THE SECOND WAS
OFF THE COAST OF CENTRAL CALIFORNIA. AT THE SURFACE...HIGH PRESSURE
WAS LOCATED OVER THE OZARKS WHILE A COLD FRONT EXTENDED FROM FAR
NWRN NORTH DAKOTA INTO CENTRAL MONTANA. BETWEEN THE APPG FRONT AND
NORTHWEST OF THE SURFACE HIGH...SRLY WINDS WERE PRESENT ACORSS
WESTERN AND NORTH CENTRAL NEBRASKA TONIGHT. WITH SRLY WINDS OF 10 TO
20 MPH ATTM...TEMPERATURES AS OF 3 AM CDT WERE VERY MILD ACROSS THE
FORECAST AREA. READINGS RANGED FROM 56 AT OGALLALA AND
IMPERIAL...TO 63 AT VALENTINE...AINSWORTH AND THEDFORD.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT FRI MAY 6 2016

OVER THE NEXT 24 HOURS...THE MAIN FORECAST CHALLENGS
ARE TEMPERATURES TODAY...FOLLOWED BY THE THREAT FOR THUNDERSTORMS IN
THE WEST AND NORTHWEST TONIGHT. FOR TODAY...THE COLD
FRONT...CURRENTLY PUSHING INTO NORTHERN NORTH DAKOTA...WILL MIGRATE
SOUTH INTO CENTRAL SOUTH DAKOTA BY THIS AFTERNOON...IMMEDIATELY
SOUTH OF THIS FEATURE...H85 TEMPS WILL REACH 22 TO 25C ACROSS FAR
NORTHWESTERN NEBRASKA AND SOUTHWESTERN SOUTH DAKOTA. TEMPS TODAY
WILL BE WARMEST ACROSS THE FAR SOUTHWESTERN CWA WHERE H85 TEMPS
REACH 24 TO 26C THIS AFTERNOON. ANOTHER AREA OF WARM TEMPS WILL BE
ACROSS FAR NORTHWESTERN AND NORTH CENTRAL NEBRASKA INVOF THE APPG
COLD FRONT. IN THESE AREAS I WENT ABOVE GUIDANCE ON TEMPS AS WE
TYPICALLY ARE WARMER WITH AN APPROACHING COLD FROPA...IE
COMPRESSIONAL WARMING. AS FOR THUNDERSTORM CHANCES LATER
TODAY...HAVE LEFT OUT MENTION OF PCPN IN THE FCST. LOOKING AT THE
NAM SOLN FOR THIS AFTERNOON...YEILDED SOME DECENT ELEVATED
INSTABILITY IN THE WEST AND SOUTHWESTERN CWA. HOWEVER...THE CAP IS
REALLY STRONG THIS AFTERNOON AND DOESN/T WEAKEN UNTIL LATER THIS
EVENING. WITH THIS IN MIND...WILL CONTINUE A DRY FCST THROUGH 00Z
SAT. FOR TONIGHT...THUNDERSTORM CHANCES WILL BEGIN TO INCREASE LATER
THIS EVENING AS THE COLD FRONT BEGINS TO PUSH INTO NORTHERN
NEBRASKA. THE MODELS CONTINUE TO DEVELOP SOME WEAK CONVECTION ALONG
AND NORTH OF THE FRONT OVERNIGHT AND HAVE PLACED MY HIGHEST POPS
ACROSS THE NORTHERN HALF OF THE CWA WHERE THE FRONT IS EXPECTED TO
BE LOCATED TONIGHT. FURTHER SOUTH...ELEVATED INSTABILITY WILL
CONTINUE OVERNIGHT...HOWEVER THERE IS NOT MUCH OF ANY LOW LEVEL
FOCUS FOR CONVECTIVE INITIATION. WITH THIS IN MIND...HAVE LIMITED
POPS TO SLIGHTS IN THE SOUTH OVERNIGHT AS THE 4KM WRF AND GFS SOLNS
HAVE SOME INDICATION OF ISOLATED STORMS LATE TONIGHT IN THE EASTERN
PANHANDLE AND SWRN NEBRASKA. THE SEVERE THREAT TONIGHT WILL BE
RATHER LIMITED AND CONFINED TO FAR NORTHWESTERN PORTIONS OF THE CWA.
DEEP LAYER SHEAR WILL BE  ON THE ORDER OF 15 TO 25 KTS THIS
AFTERNOON...INCREASING TO 30 TO 40 KTS TONIGHT. MID LEVEL LAPSE
RATES CONTINUE TO BE STEEP OVERNIGHT...SO THERE IS THAT CONTINUED
THREAT FOR LARGE HAIL.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 344 AM CDT FRI MAY 6 2016

MODELS HAVE SHIFTED THE POTENTIAL FOR SEVERE TSTMS BACK NORTHWARD
INTO SOUTHWEST NEBRASKA SATURDAY AFTERNOON AND EVENING. GFS AND HI
RES MODELS ...NAM 4KM...NAM...ARW AND NMM ALL AGREE THAT SFC LOW
PRESSURE WILL QUICKLY DEEPEN ACROSS NORTHEAST COLORADO DURING THE
DAY IN RESPONSE TO A SIGNIFICANT SHORTWAVE ROUNDING THE BASE OF THE
UPPER LEVEL LOW AND EMERGING INTO EASTERN COLORADO SATURDAY
AFTERNOON AT PEAK HEATING. A WARM FRONT WILL BE LOCATED EAST OF THE
SFC LOW ALONG A LINE FROM NEAR IMPERIAL TO CURTIS AND THEN FARTHER
EAST INTO SOUTH CENTRAL NEBRASKA...WHILE A DRY LINE WILL ARC SOUTH
FROM THE SFC LOW FROM FAR NORTHEAST COLORADO THROUGH EXTREME WESTERN
KANSAS. THIS WILL SET UP A TRIPLE POINT IN THE VICINITY OF FAR
NORTHEAST COLORADO OR FAR SOUTHWEST NEBRASKA. IT APPEARS THAT
CONVECTION WILL INITIATE NEAR THE TRIPLE POINT BY LATE AFTERNOON
SATURDAY...WITH OTHER SCT STORMS DEVELOPING SOUTHWARD ALONG THE DRY
LINE. THE STORMS NEAR THE TRIPLE POINT SHOULD QUICKLY EXPAND EAST
AND NORTHEAST ALONG AND NORTH OF THE WARM FRONT ACROSS SOUTHWEST
NEBRASKA SATURDAY EVENING. POINT SOUNDINGS IN THIS AREA SHOW
CONDITIONS QUITE UNSTABLE DUE TO ADEQUATE POOLED MOISTURE /DEW
POINTS NEARING 60F/ STEEP MID LEVEL LAPSE RATES AND SFC TEMPS IN THE
UPPER 60S TO LOWER 70S. WIND PROFILES IN THE SOUNDINGS SUPPORT
SUPERCELLS WITH ALL MODES OF SEVERE POSSIBLE INCLUDING LARGE HAIL
AND POSSIBLY A TORNADO OR TWO. THIS SITUATION WILL BE MONITORED
CLOSELY AS THE POSITION OF THE SFC LOW AND ASSOCIATED BOUNDARIES
WILL BE KEY TO WHERE THE BEST SEVERE POTENTIAL WILL RESIDE.

FORECAST CONFIDENCE REGARDING THE POTENTIAL FOR SEVERE WEATHER IS
LOW FOR SUNDAY. BOUNDARY LOCATION ETC. WILL LIKELY DEPEND ON
SATURDAY NIGHT NIGHT CONVECTION. SEEMS REASONABLE THAT AN MCS WILL
LIKELY HAVE MOVED ACROSS MOST OF THE AREA TO THE NORTH OF THE WARM
FRONT SATURDAY NIGHT...AND THIS COULD VERY WELL PUSH THE FRONTAL
BOUNDARY AND CORRESPONDING SEVERE THREAT FARTHER SOUTH IN KS SUNDAY
AFTERNOON. HOWEVER...THE UPPER LEVEL LOW IS FORECAST TO SLOWLY CROSS
THE AREA SUNDAY AFTERNOON THROUGH MONDAY. AT THE VERY LEAST EXPECT A
SCATTERING OF SHOWERS AND TSTMS SUNDAY THROUGH MONDAY...WITH LATER
FORECASTS TO DETERMINE THE LOCATION FOR ANY SEVERE TSTM ACTIVITY.

TUESDAY AND BEYOND WILL REMAIN SOMEWHAT UNSETTLED AS ANOTHER UPPER
LOW DEVELOPS INTO THE NORTHERN PLAINS. MODELS ARE CONVERGING ON A
NORTHERN TRACK WITH THIS NEXT SYSTEM...WITH A MORE WESTERLY DRYING
FLOW ALOFT ON THE SOUTH SIDE OF THE SYSTEM ACROSS OUR AREA. POPS
HAVE TRENDED DOWN TO JUST SLIGHT CHANCE FOR MIDWEEK DUE TO THE
FARTHER NORTH TRACK. IT WILL REMAIN COOL FOR MUCH OF THE WEEK...AS A
PACIFIC AIRMASS WILL GRADUALLY MIX WITH A CANADIAN AIRMASS MOVING
SOUTH ON THE BACKSIDE OF THE NORTHERN PLAINS UPPER LEVEL LOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 629 AM CDT FRI MAY 6 2016

FOR THE KLBF TERMINAL...EXPECT SCATTERED CLOUDS AROUND 25000 FT
AGL OVER THE NEXT 24 HOURS. WINDS WILL BE FROM THE SOUTH AT 10 TO
20 KTS...BECOMING SOUTHEAST AT AROUND 10 KTS THIS EVENING. FOR THE
KVTN TERMINAL...EXPECT SCATTERED TO BROKEN CIGS OF 25000 FT AGL
FOR TODAY AND THIS EVENING. LATER TONIGHT...A FRONTAL BOUNDARY
WILL PASS THROUGH NORTHERN NEBRASKA...STALLING OVER CENTRAL
NEBRASKA. THERE IS A SMALL THREAT FOR THUNDERSTORMS OVERNIGHT OVER
NORTHERN NEBRASKA. ATTM...THE THREAT IS SMALL ENOUGH TO LEAVE OUT
OF THE 12Z TAF ISSUANCE. WINDS AT THE KVTN TERMINAL WILL BE FROM
THE SOUTH AT 10 TO 20 KTS TODAY...SHIFTING TO THE NORTHEAST AT 10
KTS TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 344 AM CDT FRI MAY 6 2016

MINOR FLOODING CONTINUES ALONG THE NORTH PLATTE RIVER NEAR
LEWELLEN. THE CURRENT STAGE AT LEWELLEN IS 7.6 FEET WHICH IS JUST
OVER THE FLOOD STAGE OF 7.5 FEET. LITTLE CHANGE IN THE RIVER LEVEL
IS EXPECTED OVER THE NEXT SEVERAL DAYS. ELEVATED RIVER LEVELS WILL
CONTINUE ALONG THE SOUTH PLATTE RIVER AND THE MAIN STEM OF THE
PLATTE RIVER DOWNSTREAM OF NORTH PLATTE FOR THE NEXT SEVERAL DAYS.
AT THIS TIME...THE SOUTH PLATTE AND MAIN STEM PLATTE RIVER FROM
NORTH PLATTE TO BRADY IS EXPECTED TO REMAIN BELOW FLOOD STAGE.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...TAYLOR
AVIATION...BUTTLER
HYDROLOGY...BUTTLER



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