Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Text Only | 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 KLBF 201716
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1216 PM CDT MON OCT 20 2014

.SYNOPSIS...
ISSUED AT 357 AM CDT MON OCT 20 2014

THE 07Z SURFACE ANALYSIS SHOWED LOW PRESSURE CENTERED OVER EASTERN
LAKE SUPERIOR WITH A FRONT OR BOUNDARY DRAPED THROUGH WISCONSIN AND
IOWA TO SOUTHERN NEBRASKA. ANOTHER BOUNDARY WAS DRAPED ACROSS
MISSOURI TO NORTHEAST OKLAHOMA. PROMINENT SUBSIDENCE MANIFEST IN THE
WATER VAPOR IMAGERY INDICATED THAT THE MISSOURI BOUNDARY HAD
STRONGER UPPER SUPPORT THAN THE ONE ACROSS IOWA AND NEBRASKA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT MON OCT 20 2014

FOR TODAY...THE ONLY CLOUDINESS EXPECTED IS SCATTERED CIRRUS.
UNSEASONABLY WARM TEMPERATURES CAN BE EXPECTED AGAIN TODAY.
OVERNIGHT LOWS WILL BE ABOVE AVERAGE AS WELL. CLOUDINESS IS NOT
EXPECTED TO INCREASE MUCH TONIGHT THOUGH SOME STRATUS IS EXPECTED TO
COME INTO EASTERN COLORADO. THERE IS SOME UNCERTAINTY REGARDING THE
NORTHERN EXTENT OF IT BUT OUR CURRENT THINKING IS THAT IT WILL NOT
GET INTO WESTERN NEBRASKA TONIGHT.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 357 AM CDT MON OCT 20 2014

PRIMARY FORECAST CONCERNS FOR THIS PERIOD DEAL WITH TEMPERATURES
FOR BOTH TUESDAY AND WEDNESDAY AS WELL AS RAIN/THUNDERSTORM
CHANCES CENTERED ON WEDNESDAY.

MODELS CONTINUE TO BE IN GOOD AGREEMENT CONCERNING THE GENERAL
WEATHER PATTERN THROUGH ABOUT WEDNESDAY NIGHT. BEYOND THAT TIME
THE MAIN DIFFERENCES IN THE MODEL OUTCOMES ARE WITH THE UPPER
LEVEL TROUGH THAT MOVES ACROSS THE LOCAL AREA WEDNESDAY AND ITS
PROGRESSION EASTWARD. THEY DO AGREE WELL WITH UPPER LEVEL RIDGING
BUILDING IN OVER THE PLAINS THROUGH THE WEEKEND AS A STRONG UPPER
LEVEL LONG WAVE TROUGH APPROACHES THE WEST COAST.

BEGINNING ON TUESDAY MORNING...RIDGING ALOFT WILL BE DIRECTLY
OVERHEAD AS THE UPPER LEVEL TROUGH CURRENTLY OFF THE WEST COAST
WILL HAVE MOVED ONSHORE AND BE OVER OREGON/NEVADA. AS THE DAY
PROGRESSES THE RIDGE AXIS WILL MIGRATE EASTWARD AS THE UPPER LEVEL
TROUGH ALSO PROGRESSES EAST TOWARDS WESTERN WYOMING. THE SOUTHERLY
FLOW ALOFT WILL ALLOW WARMER AIR TO BE PULLED INTO THE PLAINS. AT
THE SURFACE...HIGH PRESSURE WILL BE LOCATED TO THE EAST OF THE
LOCAL AREA WHICH WILL LEAD TO SOUTHERLY RETURN FLOW COMING
DIRECTLY FROM THE GULF OF MEXICO...THROUGH THE HIGH PLAINS AND UP
INTO NEBRASKA. THEREFORE...THE PROCESS OF INCREASING THE MOISTURE
LOCALLY WILL BE IN PLACE WHICH WILL CONTINUE THROUGH WEDNESDAY. AT
THIS TIME...THE MODELS ARE SHOWING DEWPOINTS INCREASING INTO THE
50S...OR AT LEAST UPPER 40S. THE PRESSURE GRADIENT WILL TIGHTEN UP
THROUGH THE DAY SO EXPECTING A FAIRLY BREEZY DAY. 850MB WINDS ARE
25-40 KTS SO ASSUMING MIXING OCCURS TO AT LEAST THAT LEVEL SHOULD
GET GUSTS UP TO 40 MPH. THE NAM AND GFS ARE BOTH SHOWING THE
DEVELOPMENT OF HIGH BOUNDARY LAYER MOISTURE COMING FROM OVER
OKLAHOMA AND KANSAS AND PUSHING INTO WESTERN NEBRASKA. WITH WINDS
EXPECTED TO STAY UP OVERNIGHT AND INTO TUESDAY MORNING NO WORRIES
CURRENTLY WITH FOG SO ONLY ANTICIPATING STRATUS. DID INCREASE
CLOUD COVER IN THE FORECAST BUT HOW LONG THE CLOUDS WILL STICK
AROUND IS THE BIG QUESTION. THE MODELS WANT TO KEEP THEM AROUND
INTO THE AFTERNOON AND PERHAPS THROUGH THE DAY IN SOME PLACES. IF
THIS SCENARIO WOULD OCCUR...HIGH TEMPERATURES WOULD CERTAINLY BE
IMPACTED. THE NAM/S STATISTICAL GUIDANCE HAS BEGUN TO START
CATCHING ON WITH THIS TREND AND DID LOWER THE FORECAST HIGHS FOR
TUESDAY SIGNIFICANTLY. REALLY DON/T HAVE A GOOD FEEL FOR IF THIS
WILL ACTUALLY OCCUR SO DIDN/T WANT TO GO TOO LOW WITH MAX
TEMPERATURES...BUT DID GO DOWN A FEW DEGREES.

THE UPPER LEVEL SHORTWAVE TROUGH WILL THEN PASS ACROSS THE PLAINS
WEDNESDAY AND WEDNESDAY EVENING. CONTINUED THE SLIGHT CHANCES FOR
RAIN SHOWERS LATE TUESDAY NIGHT...BUT THERE ARE DIFFERENCES IN
WHEN ANY RAIN WILL MOVE IN. ALTHOUGH THE NAM IS DRY INTO THE DAY
WEDNESDAY...WANTED TO ACCOUNT FOR THE SMALL CHANCE OF GETTING A
SHOWER OVER THE WESTERN PART OF THE FORECAST AREA. AS THE SYSTEM
MOVES OVERHEAD...A COLD FRONT WILL MOVE THROUGH AT THE SURFACE WITH
THAT BOUNDARY BEING THE FOCUS FOR CONVERGENCE AND
SHOWER/THUNDERSTORM DEVELOPMENT. CROSS SECTIONS ARE SHOWING A STRONG
OMEGA SIGNAL ON WEDNESDAY...BUT FORECAST SOUNDINGS ARE NOT SHOWING
ANY DEVELOPMENT OF INSTABILITY UNTIL THE AFTERNOON HOURS. FOR THESE
REASONS...KEPT CHANCES OF RAIN THROUGH THE MORNING...THEN RAIN WITH
ISOLATED THUNDER IN THE AFTERNOON. ACTIVITY THROUGH THE MORNING WILL
LIKELY BE MORE SCATTERED...THEN AS THE INSTABILITY BUILDS SHOULD GET
MORE OF A CHANCE FOR THUNDER IN AFTERNOON. AS HAS BEEN ADVERTISED
OVER THE PAST FEW DAYS...PRECIPITABLE WATER VALUES INCREASE TO OVER
2 STANDARD DEVIATIONS ABOVE NORMAL SO CAN/T DISCOUNT SOME LOCALIZED
HEAVY RAINS WITH PASSING SHOWERS AND STORMS.

TEMPERATURES FOR WEDNESDAY ARE ALSO A BIT PROBLEMATIC AS THE
THOUGHTS ARE IT WILL BE QUITE CLOUDY THROUGH THE DAY. HOWEVER
MODEL GUIDANCE PUTS HIGHS UP INTO THE MID AND UPPER 70S AGAIN FOR
PORTIONS OF THE AREA. JUST FEEL THAT THERE NEEDS TO BE FULL
SUNSHINE TO REACH THOSE NUMBERS AND WITH SHOWERS IN THE AREA AS
WELL...THINK HIGHS AROUND 70 DEGREES WILL BE AS HIGH AS IT WILL GET.
SO ESSENTIALLY DISREGARDED THE GUIDANCE NUMBERS AT THIS POINT.

THEN MOVING ON THROUGH THE END OF THE WEEK...THE SHORTWAVE TROUGH
MOVES EAST AND OUT OF THE REGION ALLOWING FOR UPPER LEVEL RIDGING
TO BUILD INTO CENTRAL PART OF THE COUNTRY AS ANOTHER DEEP LONGWAVE
TROUGH MOVES INTO THE EASTERN PACIFIC. THIS RIDGE LOOKS TO BE
STRONGER YET...WITH THE ECMWF EVEN INCREASING 850MB TEMPERATURES
TO 21C ON SATURDAY ACROSS MUCH OF THE FORECAST AREA. THIS WOULD BE
MUCH MORE SUMMER LIKE CONDITIONS RATHER THAN THE END OF OCTOBER.
THE CURRENT FORECAST DOESN/T GO TERRIBLY WARM YET...BUT HAVE
TRENDED TEMPERATURES A BIT WARMER THROUGH THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1216 PM CDT MON OCT 20 2014

VFR CONDITIONS TO CONTINUE ACROSS ALL WESTERN AND NORTH CENTRAL
NEBRASKA TERMINALS THROUGH MUCH OF THE 18Z FORECAST PERIOD.
HOWEVER GUIDANCE DOES INDICATE INCREASING BL MOISTURE WHICH MAY
LEAD TO THE DEVELOPMENT OF STRATUS ACROSS SOUTHWEST NEBRASKA AFTER
09Z TUESDAY. CONFIDENCE IN MVFR STRATUS IMPACTING THE KLBF
TERMINAL IS NOT SUFFICIENT ENOUGH FOR A MENTION IN THE OFFICIAL
FORECAST YET...BUT WILL BE WATCHED.

&&

.FIRE WEATHER...
ISSUED AT 357 AM CDT MON OCT 20 2014

THE RELATIVE HUMIDITY YESTERDAY WAS AROUND 20 PERCENT FOR MUCH OF
WESTERN NEBRASKA WITH TEMPERATURES IN THE UPPER 70S AND DEWPOINTS OF
35 TO 40. FOR TODAY...PROJECTED DEWPOINTS OF 40-45 AND TEMPERATURES
IN THE LOW TO MID 70S WILL RESULT IN RELATIVE HUMIDITY OF 25-30
PERCENT THIS AFTERNOON IN MUCH OF WESTERN AND NORTH CENTRAL NEBRASKA
WHICH IS ABOVE CRITICAL FIRE DANGER THRESHOLDS. WIND...WHICH IS
EXPECTED TO BE LESS THAN 15 MPH OVER MOST OF THE AREA...WILL NOT
REACH CRITICAL VALUES EITHER. SO...WE DO NOT EXPECT CRITICAL FIRE
CONDITIONS TODAY.

&&

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

$$

SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...BROOKS
AVIATION...JACOBS
FIRE WEATHER...SPRINGER








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