Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 211711
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1211 PM CDT TUE OCT 21 2014

.UPDATE...
ISSUED AT 656 AM CDT TUE OCT 21 2014

AS DISCUSSED IN THE MAIN DIATRIBE BELOW...HOURLY TEMP TRENDS HAVE
BEEN A PAIN THIS MORNING AS MANY AIRPORT SITES CONTINUE TO
FLUCTUATE SEVERAL DEGREES IN A SHORT TIME IN RESPONSE TO FAIRLY
SUBTLE COUPLING/DECOUPLING OF THE NEAR-SURFACE LAYER AS LIGHT
BREEZES COME AND GO. IN GENERAL THOUGH...MOST OF THE CWA (WITH THE
INTERESTING EXCEPTION OF THE AIRPORT SENSORS AT GRAND
ISLAND/HASTINGS) HAVE BOTTOMED OUT A BIT COLDER THAN EXPECTED
SEVERAL HOURS AGO...AND ACTUAL LOWS FOR MOST OF THE CWA WILL
OFFICIALLY GO DOWN IN THE 38-45 RANGE MOST AREAS...AND EVEN AS
BRIEFLY COLD AS 36 AT ORD. OTHERWISE...AS WAS SUSPECTED ANY KIND
OF MENTIONABLE FOG HAS BEEN A NON-ISSUE LOCALLY...AND ALTHOUGH
PATCHES OF LOWER STRATUS HAVE BEEN GRADUALLY INCREASING JUST TO
THE SOUTH-SOUTHWEST OF THE CWA...THE JURY IS STILL OUT ON WHETHER
IT BECOMES WIDESPREAD ENOUGH TO APPRECIABLY AFFECT SKY COVER AS
THE DAY WEARS ON.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM CDT TUE OCT 21 2014

THE PRIMARY ISSUES/QUESTIONS DURING THE NEXT 24 HOURS INVOLVE 1)
TO WHAT EXTENT (IF MUCH OF ANY) WILL A LOWER STRATUS DECK POSSIBLY
AFFECT MAINLY THE SOUTHWESTERN 1/2 OF THE CWA TODAY AND INTERRUPT
AN OTHERWISE MOSTLY SUNNY DAY...2) TO WHAT EXTENT MIGHT AT LEAST
PATCHY FOG DEVELOP TONIGHT IN INCREASING LOW LEVEL
MOISTURE...ALTHOUGH FAIRLY STEADY SOUTHERLY BREEZES SHOULD KEEP
SIGNIFICANT VISIBILITY REDUCTIONS AT BAY. THE SHORT ANSWER TO
NUMBER 1 IS THAT THE OFFICIAL FORECAST IS OPTIMISTICALLY GEARED
TOWARD A NO-WORSE-THAN- PARTLY CLOUDY DAY AS A WHOLE AND REGARDING
NUMBER 2...CAME VERY CLOSE TO TOSSING A GENERIC PATCHY FOG MENTION
INTO THE FORECAST FOR LATE TONIGHT BUT OPTED AGAINST IT FOR NOW
AND WILL GIVE NEXT FEW SHIFTS ANOTHER LOOK AT THE POTENTIAL FOR
REASONS OUTLINED IN MORE DETAIL BELOW. OTHERWISE...CONFIDENCE
REMAINS QUITE HIGH IN A MILD AND DRY 24 HOURS (ESPECIALLY THROUGH
THIS EVENING) WITH THE MAIN FEATURE OF NOTE TODAY BEING INCREASING
SOUTHERLY WINDS.

STARTING OFF EARLY THIS MORNING AT 0830Z/330AM...SKIES ARE
ESSENTIALLY CLOUD-FREE CWA-WIDE...WITH 11-3.9 MICRON SATELLITE
INDICATING ONLY A NARROW RIBBON OF STRATUS SLOWLY DRIFTING NORTH
THROUGH SOUTHERN KS BUT STILL WELL-SOUTH OF THE LOCAL AREA. AT THE
SURFACE...08Z OBJECTIVE ANALYSIS PLACES THE CWA JUST ON THE
BACKSIDE OF A BROAD RIDGE AXIS CENTERED OVER THE MO VALLEY...BUT
WITH THIS RIDGE STILL CLOSE ENOUGH TO THE AREA TO KEEP BREEZES IN
THE NEAR-CALM TO GENERALLY LESS-THAN-6 MPH FROM THE SOUTH VARIETY.
AS IS TYPICAL IN THESE CLEAR SKY/SLIGHTLY VARIABLE BREEZE
REGIMES...TEMPS HAVE BOUNCED AROUND RATHER RANDOMLY...WITH THE
LATEST OBS INDICATING A RANGE FROM NEAR-40 TO NEAR-50 ACROSS THE
CWA...ALTHOUGH A FEW PLACES MAINLY IN THE FAR EAST HAVE EVEN
TOUCHED THE UPPER 30S. WHEN ALL IS SAID AND DONE...MOST PLACES
SHOULD END UP WITH OVERNIGHT LOWS SOMEWHERE IN THE 39-46 RANGE BUT
WITH SOME WARMER EXCEPTIONS VERY POSSIBLE. IN THE MID-UPPER LEVEL
SCENE...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRMS
THAT THE CWA STILL LIES UNDER A BROAD RIDGE AXIS EXTENDING NORTH-
SOUTH THROUGH THE HEART OF THE NATION...ALTHOUGH A VIGOROUS
SHORTWAVE TROUGH IS SLOWLY-BUT-SURELY APPROACHING THE NORTH
CENTRAL CONUS FROM THE NV/ID BORDER AREA AND OBVIOUSLY WILL PLAY A
LARGER ROLE IN OUR WEATHER FOR WED DAY-NIGHT AS DESCRIBED IN THE
LONG TERM BELOW.

SWITCHING GEARS TO THE FORWARD-LOOKING FORECAST AND STARTING WITH
EARLY THIS MORNING...AS HINTED IN THE UPDATE DISCUSSION A FEW
HOURS AGO HAVE OPTED TO OFFICIALLY PULL THE MENTION OF PATCHY FOG
IN FAR SOUTHERN/SOUTHWEST ZONES (MAINLY KS)...AS CURRENT OBS AND
SHORT-TERM VSBY PRODUCTS FROM THE RAP13/HRRR STRONGLY SUGGEST THAT
ANY FOG WORTH MENTIONING SHOULD FOCUS AT LEAST 50-75 MILES
SOUTH/ESPECIALLY SOUTHWEST OF THE CWA WHERE HIGHER DEWPOINTS MORE
SO INTO THE MID-40S ARE FOCUSED.

GETTING PAST SUNRISE AND THROUGH THE DAYLIGHT HOURS...CONFIDENCE
REMAINS HIGH IN DRY CONDITIONS...AS EVEN THOUGH THERE WILL
ACTUALLY BE SOME WEAK LOW-MID LEVEL INSTABILITY RETURNING TO
MAINLY SOUTHWEST PORTIONS OF THE CWA IT SHOULD REMAIN CAPPED AS
FORCING REMAINS NEGLIGIBLE. THIS IS LARGELY IN PART BECAUSE THE
MID-UPPER LEVEL PICTURE CONTINUES TO BE DOMINATED BY THE SLOWLY-
DEPARTING RIDGE AXIS...AND EVEN BY DAY/S END THE MAIN WESTERN
CONUS SHORTWAVE TROUGH IS ONLY PROGGED TO REACH THE CENTRAL
MT/WESTERN WY AREA. AT THE SURFACE TODAY...A GRADUALLY INCREASING
PRESSURE GRADIENT BETWEEN THE DEPARTING HIGH AND A CLASSIC HIGH
PLAINS LEE TROUGH TO THE WEST WILL PROMOTE INCREASING SOUTHERLY
BREEZES...ALTHOUGH IT WILL BE TOWARD MID-DAY AND ESPECIALLY THIS
AFTERNOON BEFORE BREEZES REALLY AMOUNT TO MUCH. ONCE THEY KICK
IN...SUSTAINED SPEEDS SHOULD GENERALLY AVERAGE 10-15 MPH IN
EASTERN ZONES AND 15-20 MPH IN WESTERN ZONES WITH TYPICALLY HIGHER
GUSTS GENERALLY 5-10 MPH ABOVE SUSTAINED. AS EARLIER TOUCHED
ON...THE MAIN CAVEAT TODAY IS WHETHER OR NOT ENOUGH SATURATION
WILL TAKE PLACE TO DRIVE AT LEAST A LOCALIZED ZONE OF PASSING
THICKER LOWER STRATUS INTO ESPECIALLY THE SOUTHWESTERN CWA...OR
WHETHER ENOUGH MIXING WILL BE PRESENT TO KEEP ANY POTENTIAL
STRATUS AS NO-WORSE-THAN SCATTERED COVERAGE. THERE ARE SOME MIXED
MESSAGES ON THIS...BUT AT LEAST FOR NOW THE SKY COVER FORECAST
LEANS OPTIMISTIC ESPECIALLY FOR THE NORTHEAST 1/2 OF THE CWA WITH
VERY LITTLE CLOUD COVER AT ALL ANTICIPATED THERE. BASED ON THE
CURRENT SKY COVER ASSUMPTIONS...HIGH TEMPS WERE ONLY TWEAKED
SLIGHTLY FROM PREVIOUS FORECAST...AIMING FOR GENERALLY MID-70S
MOST AREAS AND MAYBE SOME UPPER 70S SOUTHWEST (ASSUMING OF COURSE
THAT SKY COVER DOESN/T END UP BEING MORE OF AN ISSUE THAN
CURRENTLY THOUGHT). ALTHOUGH NOT ALL THAT MUGGY BY ANY
MEANS...DEWPOINTS TODAY ARE PROGGED TO CLIMB INTO THE MID-40S TO
MID-5OS RANGE (HIGHEST SOUTHWEST).

TURNING TO THIS EVENING/TONIGHT...KEPT THE OFFICIAL FORECAST VOID
OF ANY RAIN MENTION...BUT SHOULD AT LEAST POINT OUT THAT "SILENT"
5-10 PERCENT POPS ARE INDICATED FOR PORTIONS OF THE CWA POST-
MIDNIGHT AS THERE IS JUST ENOUGH FORCING/MOISTURE ADVECTION IN
PLACE ALONG THE EASTERN EDGES OF A LOW-MID LEVEL WIND MAXIMUM
PRESENT IN THE 850-700 MILLIBAR LAYER THAT SUPPOSE A FEW ROGUE
SPRINKLES/SHOWERS CANNOT BE 100 PERCENT RULED OUT. THAT BEING SAID
THOUGH...MODEL CONSENSUS (INCLUDING 4KM WRF-NMM/ARW SIMULATED
REFLECTIVITY) STRONGLY SUGGESTS THAT ANY LIMITED COVERAGE OF LATE
NIGHT RAIN WOULD FOCUS EITHER NORTHEAST AND/OR ESPECIALLY SLIGHTLY
WEST OF THE CWA WITHIN WESTERN/NORTH CENTRAL NEB. IN THE LARGER
SCALE MID-UPPER LEVEL PICTURE...THE LEADING EDGES OF IMPULSES
ASSOCIATED WITH THE INCOMING WAVE REACHES WESTERN NEB/NORTHWEST KS
BY NIGHTS END...BUT LARGE-SCALE FORCING REMAINS WEAK LOCALLY AS
THE MAIN VORT MAX WITH THE SYSTEM STILL COMES NO CLOSER THAN
EASTERN MT/WY DURING THIS TIME. AS FOR SURFACE BREEZES
TONIGHT...THE ENHANCED PRESSURE GRADIENT AHEAD OF THE APPROACHING
SYSTEM ALONG WITH SOME LIMITED MIXING INTO A LOW LEVEL JET WILL
KEEP SOUTH-SOUTHEAST BREEZES FAIRLY STEADY MOST OF THE
NIGHT...GENERALLY 10-15 MPH. THESE STEADY BREEZES ARGUE FAIRLY
CONVINCINGLY AGAINST SIGNIFICANT FOG ISSUES...BUT NEXT FEW SHIFTS
MAY HAVE TO CONSIDER INTRODUCING A TOKEN PATCHY FOG MENTION AS
NEIGHBORING OFFICES GLD/DDC HAVE ALREADY DONE IF IT APPEARS THE
NAM AND ASSOCIATED SREF/MET GUIDANCE VISIBILITY END UP BEING ONTO
SOMETHING...ALTHOUGH THE LATEST GFS-BASED MAV GUIDANCE CERTAINLY
DOWNPLAYS FOG POTENTIAL. FOR WHAT ITS WORTH...THE LATEST 03Z SREF
PROBABILITY-OF-VISIBILITY BELOW 3 MILES PRODUCT IS ONLY MODESTLY-
SUPPORTIVE OF FOG. AT ANY RATE...EVEN IF FOG IS HELD TO A MINIMUM
AS CURRENTLY EXPECTED THERE SHOULD BE GRADUALLY INCREASING CLOUD
COVER TONIGHT EITHER OF THE LOWER STRATUS AND/OR HIGHER CIRRUS
VARIETY. THE COMBO OF INCREASED MOISTURE...STEADY BREEZES AND
INCREASING CLOUDS ASSURES A MILDER NIGHT THAN THE ONGOING
ONE...AND ACTUALLY NUDGED UP FORECAST LOW TEMPS GENERALLY 1-3
DEGREES FROM PREVIOUS IN MOST LOCATIONS...AIMING MOST OF THE CWA
INTO THE 53-56 RANGE WHICH IS SOLIDLY 10-15 DEGREES ABOVE AVERAGE
FOR THE DATE.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 435 AM CDT TUE OCT 21 2014

ABOVE NORMAL TEMPERATURES ARE EXPECTED TO PERSIST THROUGH THE
REMAINDER OF THIS WEEK AND INTO NEXT WEEKEND BEFORE WE SEE A RETURN
TO MORE NORMAL TEMPERATURES BY EARLY NEXT WEEK. NORMAL HIGH
TEMPERATURES FOR THIS TIME OF YEAR ARE GENERALLY IN THE LOWER
60S...WHILE HIGHS THROUGH SUNDAY ARE EXPECTED TO RISE AT LEAST INTO
THE 70S.

MOST OF THE FORECAST PERIOD WILL BE DRY...WITH A NOTABLE EXCEPTION
WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING WHEN WIDESPREAD
PRECIPITATION IS LIKELY ACROSS THE FORECAST AREA IN ASSOCIATION WITH
AN UPPER LEVEL SHORT WAVE AND AN ACCOMPANYING SFC TROUGH.

WEDNESDAY/WEDNESDAY NIGHT...FORECAST MODELS CONTINUE TO INDICATE A
HIGH LIKELIHOOD OF WIDESPREAD PRECIPITATION AS AN UPPER SHORT WAVE
AND SFC TROUGH TRACK EAST ACROSS THE FORECAST AREA. MOST OF THE RAIN
WILL FALL WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING WITH THE RAIN
PUSHING EAST OF THE AREA BY LATE WEDNESDAY NIGHT. RAIN SHOWERS WILL
FORM ALONG THE SFC TROUGH IN AN AREA OF ENHANCED FRONTOGENESIS. THE
FORCING WILL BE ORIENTED FROM NORTHEAST TO SOUTHWEST AND WILL SLIDE
EAST THROUGH THE AFTERNOON AND EVENING HOURS. THIS WILL LIKELY
RESULT IN A QUICK SEVERAL HOURS OF RAINFALL. INSTABILITY IS LIMITED
WITH MLCAPE VALUES ONLY AROUND 500 J/KG WEDNESDAY AFTERNOON. GIVEN
AT LEAST SOME INSTABILITY WILL CONTINUE TO INCLUDE THE CHANCE FOR
ISOLATED THUNDERSTORMS EMBEDDED WITHIN THE MORE WIDESPREAD BAND OF
GENERAL RAIN SHOWERS. WIND SHEAR IS ALSO NOT OVERLY IMPRESSIVE AND
CONSEQUENTLY...SEVERE WEATHER IS NOT ANTICIPATED. RAINFALL AMOUNTS
SHOULD AVERAGE OUT BETWEEN 0.10 AND 0.50 INCHES ACROSS MOST OF THE
FORECAST AREA.

THURSDAY THROUGH SATURDAY...AN UPPER LEVEL RIDGE WILL BUILD ACROSS
THE PLAINS RESULTING IN WARM AND DRY CONDITIONS. FRIDAY WILL LIKELY
BE THE WARMEST DAY OF THE WEEK AS WE ARE CENTERED RIGHT BENEATH THE
UPPER RIDGE AXIS RESULTING IN HIGHS RANGING FROM THE MID 70S TO
AROUND 80. THURSDAY AND SATURDAY...ALTHOUGH NOT AS WARM AS FRIDAY
SHOULD STILL SEE HIGHS IN THE 70S.

SUNDAY INTO MONDAY...THE UPPER LEVEL RIDGE WILL SLIDE EAST INTO THE
EASTERN CONUS...WHILE AN UPPER TROUGH TRACKS FROM THE WESTERN CONUS
INTO THE PLAINS. WE COULD SEE A COLD FRONT LOCATED EITHER OVER OUR
FORECAST AREA OR NEAR OUR FORECAST AREA ON SUNDAY WITH EVEN COOLER
WEATHER POSSIBLE BY MONDAY AS THE COLD FRONT WILL MOST LIKELY HAVE
PASSED SOUTHEAST OF US BY THAT TIME. CAN NOT RULE OUT A CHANCE OF A
RAIN SHOWER SUNDAY NIGHT INTO MONDAY WITH THIS SYSTEM...BUT A
SUPERBLEND OF MULTIPLE MODELS INDICATES MOST AREAS WILL LIKELY BE
DRY.

&&

.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1207 PM CDT TUE OCT 21 2014

SOUTHERLY WINDS WILL INCREASE DURING THE AFTN WITH GUSTS AROUND
20KTS POSSIBLE. CLOUDS WILL BE ON THE INCREASE DURING THE
OVERNIGHT HOURS AHEAD OF AN APPROACHING UPPER TROUGH AND COOL
FRONTAL BOUNDARY. CIGS MAY DROP TO MVFR LEVELS TOWARD MORNING AND
THERE IS THE POTENTIAL FOR FOG DEVELOPMENT...HOWEVER DID NOT
REDUCE VSBYS MUCH DUE TO THE EXPECTED STEADY SOUTHERLY WINDS. AS
THE FRONT APPROACHES CHANCES FOR RAIN SHOWERS DEVELOP TOWARD THE
LATTER TAF HOURS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.

&&

$$

UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...FAY



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