Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Graphics & Text | 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 261144
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
644 AM CDT WED AUG 26 2015

.SYNOPSIS...
ISSUED AT 347 AM CDT WED AUG 26 2015

THE UA PATTERN ACROSS THE CONUS TONIGHT WAS HIGHLIGHTED
BY HIGH PRESSURE OVER COLORADO WITH A RIDGE EXTENDING INTO THE
PRAIRIE PROVINCES OF CANADA. UPSTREAM OF THE RIDGE...CLOSED LOW
PRESSURE WAS PRESENT OFF THE BRITISH COLUMBIA COAST WITH A
POSITIVELY TILTED TROUGH OF LOW PRESSURE EXTENDED SWD INTO THE NERN
PACIFIC. DOWNSTREAM OF THE RIDGE...CLOSED LOW PRESSURE WAS LOCATED
ALONG THE QUEBEC/ONTARIO BORDER WITH A TROUGH EXTENDING SWD INTO THE
SRN APALACIANS. WV IMAGERY OVERNIGHT HAS A NICE DISTURBANCE
LIFTING NORTH ACROSS UT ON THE WESTERN PERIPHERY OF THE HIGH. HIGH
CLOUDINESS NORTH AND EAST OF THE DISTURBANCE...HAS SPREAD INTO
WYOMING AND MONTANA OVERNIGHT...AND WAS BEGINNING TO APPROACH
WESTERN SD AND NWRN NEBRASKA OVER THE PAST COUPLE OF HRS. AT THE
SURFACE...HIGH PRESSURE WAS LOCATED OVER THE UPPER MISSISSIPPI
VALLEY AND EXTENDED SWD INTO NORTHERN MISSOURI. A SURFACE TROUGH OF
LOW PRESSURE EXTENDED SWD FROM NORTHERN WYOMING...SSEWD INTO EASTERN
COLORADO. WINDS TONIGHT WERE LIGHT FROM THE SOUTH OR SOUTHEAST
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA AND 3 AM TEMPERATURES
RANGED FROM 59 AT VALENTINE TO 68 AT IMPERIAL.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT WED AUG 26 2015

OVER THE NEXT 24 HOURS...TEMPERATURES TODAY...FOLLOWED BY THE
THREAT FOR STORMS TONIGHT WILL BE THE MAIN FORECAST CONCERNS. FOR
TODAY...UPPER LEVEL HIGH PRESSURE ACROSS COLORADO...WILL BEGIN TO
BREAK DOWN AS A STRONG DISTURBANCE LIFTS FROM UTAH INTO WYOMING
AND WESTERN COLORADO. WARM AIR IN ASSOCIATION WITH THE HIGH...WILL
PUSH EAST INTO EASTERN COLORADO AND WESTERN NEBRASKA THIS
AFTERNOON. AT THE SAME TIME...SURFACE LOW PRESSURE WILL DEVELOP
AND DEEPEN OVER EASTERN WYOMING. SOUTH OF THE LOW...SWRLY WINDS
WILL INCREASE ACROSS EASTERN COLORADO AND SWRN NEBRASKA THIS
AFTERNOON...FORCING A DRYLINE INTO WESTERN SECTIONS OF THE
FORECAST AREA. THE COMBINATION OF VERY WARM H85 TEMPS AON 32C IN
SWRN NEBRASKA...COUPLED WITH DRY AIR BEHIND THE DRYLINE...WILL
PUSH HIGHS TO NEAR THE CENTURY MARK ACROSS FAR SWRN NEBRASKA TDY.
BOTH THE MAV AND MET GUIDANCE ARE IN GOOD AGREEMENT WITH HIGHS TDY
WEST OF THE DRYLINE...WITH AROUND 100 FORECAST FOR IMPERIAL. FCST
SOUNDINGS ALSO INDICATE A WELL MIXED ENVIRONMENT ACROSS NERN
COLORADO AND SWRN NEBRASKA THIS AFTERNOON...WITH MIXING UP TO H7.
FURTHER EAST ALONG THE HIGHWAY 83 CORRIDOR FROM NORTH PLATTE TO
VALENTINE...SB CAPES REACH 3500 TO 4500 J/KG DURING PEAK HEATING.
HOWEVER...FCST SOUNDINGS ARE INDICATIVE OF A STRONG CAPPING
INVERSION-COLOCATED WITH THE HIGH CAPES...WHICH DOES NOT BREAK
THIS AFTERNOON AND EVENING. FOR THIS AFTERNOON AND EARLY THIS
EVENING...LARGELY WENT WITH A DRY FCST...WITH THE EXCEPTION IN THE
FAR NORTHWEST...WHERE SOME COOLER AIR ALOFT BEGINS TO APPROACH THE
AREA BY EVENING AS SHORTWAVE ENERGY EMERGES FROM WYOMING INTO NWRN
NEBRASKA. FURTHER SOUTH...I DID INCLUDE A SMALL MENTION OF
THUNDERSTORMS ALONG THE DRYLINE IN THE EASTERN PANHANDLE AND FAR
SWRN NEBRASKA GIVEN THE WELL MIXED ENVIRONMENT THIS AFTN. FOR
TONIGHT...MORE ORGANIZED CONVECTION WILL BEGIN TO BREAK OUT OVER
SRN SD AND NRN NEBRASKA OVERNIGHT...AS SHORTWAVE ENERGY LIFTS OVER
A WARM FRONT SITUATED ALONG THE SD/NEBR BORDER. A 50+KT LOW LEVEL
JET WILL NOSE INTO NRN NEBR/SRN SD AS WELL AND WILL PROVIDE ADDTL
LIFT FOR PCPN OVERNIGHT. SRLY WINDS WILL CONTINUE INTO THE
OVERNIGHT WITH LOW PRESSURE SITUATED OVER THE NORTHERN PANHANDLE.
PERSISTENT WINDS OVERNIGHT...COUPLED WITH LOW LEVEL MOISTURE AND
CLOUD COVER IN NORTHERN NEBRASKA...WILL LEAD TO MILD TEMPS
OVERNIGHT WITH FCST LOWS MAINLY IN THE LOWER TO MID 60S.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 347 AM CDT WED AUG 26 2015

POTENT SHORTWAVE ALOFT WILL BE CROSSING NE/SD REGION THURSDAY AND
THURSDAY NIGHT. THE SYSTEM CLOSES OFF AT H700MB...AND MODELS IN
DECENT AGREEMENT TRACKING THE H700MB CENTER ACROSS NORTHERN
NEBRASKA/SOUTHERN SOUTH DAKOTA THURSDAY AFTERNOON AND THURSDAY
EVENING. A SURFACE LOW WILL ACCOMPANY THE UPPER SYSTEM. THE OFFICIAL
FORECAST HAS THE SURFACE LOW TRACKING SLOWLY EASTWARD ACROSS THE
SANDHILLS THURSDAY AFTERNOON...MOVING INTO EASTERN PORTIONS OF NORTH
CENTRAL NEBRASKA THURSDAY EVENING. A SURFACE TROUGH WILL EXTEND
SOUTHWARD FROM THE SURFACE LOW...AND WILL BE A FOCUS FOR AFTERNOON
SURFACE BASED TSTM ACTIVITY. DURING PEAK HEATING/INITIATION
TIME...THE SURFACE TROUGH SHOULD BE LOCATED ALONG HIGHWAY 83 FROM
THEDFORD TO NORTH PLATTE. THIS IS WHERE SFC BASED TSTM DEVELOPMENT
WILL LIKELY INITIATE...STORMS WILL INCREASE IN COVERAGE AS THEY PUSH
EASTWARD INTO CENTRAL AND EASTERN NEBRASKA DURING THE EVENING. IN
ADDITION...A WARM FRONT WILL BE LOCATED TO THE EAST OF THE SFC LOW
ACROSS NORTH CENTRAL NEBRASKA INVOF OF ONEILL/CHAMBERS/EWING. THIS
WILL LIKELY SERVE AS AN ADDITIONAL FOCUS FOR TSTM ACTIVITY. UPPER
LEVEL FORCING APPEARS QUITE IMPRESSIVE WITH THIS SYSTEM...AND ENOUGH
SHEAR IS PRESENT THROUGH THE ATMOSPHERE TO GET A FEW SEVERE STORMS
WITH LARGE HAIL AND PERHAPS DAMAGING WIND GUSTS. THIS WILL MOST
LIKELY OCCUR AS LOW LEVEL LAPSE RATES STEEPEN ALONG AND AHEAD OF THE
SURFACE TROUGH AND NEAR THE WARM FRONT DURING THE AFTERNOON INTO THE
EARLY EVENING HOURS. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE...AS
A MOIST ATMOSPHERE WILL BE IN PLACE.

SYSTEM WILL MOVE EAST OF THE AREA FRIDAY...WITH UPPER LEVEL RIDGING
EXPANDING NORTH ACROSS THE CENTRAL AND WESTERN HIGH PLAINS DURING
THE WEEKEND. THIS WILL BRING WARM TEMPERATURES WITH HIGHS IN THE MID
80S TO LOWER 90S. LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED AS
MID LEVEL TEMPERATURES WARM.

BY EARLY NEXT WEEK...A LONG WAVE TROUGH WILL DEVELOP ACROSS THE
WESTERN CONUS...WITH THE FLOW ALOFT BECOMING SOUTHWEST ACROSS THE
REGION AHEAD OF THIS TROUGH. THE BEST UPPER LEVEL FORCING WILL
REMAIN WEST OF THE REGION FOR THE MOST PART...BUT A FEW LATE DAY
STORMS MAY MOVE EAST OF THE HIGHER TERRAIN INTO THE AREA BY
TUESDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 644 AM CDT WED AUG 26 2015

FOR THE KLBF TERMINAL...EXPECT MAINLY CLEAR SKIES WITH SOME
INCREASING HIGH CLOUDINESS THIS EVENING. WINDS WILL BE FROM THE
SOUTH OR SOUTHEAST AT 10 TO 15 KTS. FOR THE KVTN TERMINAL...SKIES
WILL BE MAINLY CLEAR THROUGH 00Z THURSDAY. AFTER 00Z
THURSDAY...THERE WILL BE AN INCREASED THREAT FOR THUNDERSTORMS
AFTER 02Z THURSDAY WITH THE THREAT CONTINUING THROUGH 08Z. CIGS IN
THE VICINITY OF THUNDERSTORMS MAY REACH 5000 FT AGL WITH VISBYS
AS LOW AS 4SM. SINCE THIS IS TOWARD THE LATTER HALF OF THE
FORECAST PERIOD AND THERE ARE SOME TIMING ISSUES WITH RESPECT TO
THE MODELS...WILL UTILIZE A PROB 30 GROUP FROM 02Z TO 08Z THURSDAY
FOR THE MENTION OF THUNDERSTORMS.

&&

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

$$

SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...TAYLOR
AVIATION...CLB



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