Area Forecast Discussion
Issued by NWS Hastings, NE

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000
FXUS63 KGID 262303
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
603 PM CDT SAT JUL 26 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CDT SAT JUL 26 2014

THERE ARE 2 MAIN ISSUES DURING THE NEXT 24 HOURS...BOTH OF WHICH
ARE PRIMARILY FOCUSED DURING THESE FIRST 6-12 HOURS. ON THE MORE
UNCERTAIN SIDE OF THINGS...THE BIG QUESTION IS HOW MUCH (IF HARDLY
ANY) OF THE CWA WILL SEE THE DEVELOPMENT OF STRONG TO POTENTIALLY
SEVERE CONVECTION MAINLY BEFORE SUNSET THIS EVENING...WITH THE
MOST FAVORED AREA BEING THE EASTERN HALF AS THE DECENTLY-STRONG
COLD FRONT FOR THIS TIME OF YEAR CONTINUES PASSING THROUGH.
NEEDLESS TO SAY...POPS ARE NO HIGHER THAN 20-30 PERCENT MEANING
THAT THE VAST MAJORITY OF THE AREA LIKELY STAYS STORM-FREE...BUT
THE SITUATION NEEDS MONITORED FOR AT LEAST AN ISOLATED SEVERE
STORM. SPEAKING OF THE COLD FRONT...THOSE FOLKS WHO HAVE GROWN
WEARY OF THE PARTICULARLY WARM/HOT AND MUGGY AIRMASS THESE PAST
FEW DAYS WILL NOTICE A DECENT DROP IN TEMPERATURES AND EVEN LARGER
DROP IN DEWPOINTS/HUMIDITY FOR TOMORROW. IN THE MEANTIME...THESE
NEXT SEVERAL HOURS FEATURE THE CONTINUATION OF ONE LAST DAY OF
NEAR-ADVISORY TO ADVISORY-LEVEL HEAT INDEX VALUES.

STARTING OFF AT 20Z/3PM THIS AFTERNOON...WATER VAPOR IMAGERY AND
SHORT TERM MODEL DATA CONFIRM THAT THE LOCAL REGION IS ALONG THE
INTERFACE BETWEEN WEAK FLOW ASSOCIATED WITH AN EAST-WEST ORIENTED
SUBTROPICAL HIGH/RIDGE CENTERED ALONG AN AXIS FROM AZ/NM THROUGH
AR/LA...AND SEASONABLY STRONG FLOW CENTERED OVER NORTHERN NEB/
THE DAKOTAS/UPPER MIDWEST THAT CONCENTRATES SOUTH OF THE TRACK OF
A WELL-DEFINED CLOSED LOW CHURNING EAST-SOUTHEAST ACROSS FAR
SOUTHERN MANITOBA. EMBEDDED WITHIN THIS INTERFACE OVER THE LOCAL
AREA...LOW-AMPLITUDE DISTURBANCES ARE RIPPLING THROUGH...INCLUDING
ONE ALONG THE EASTERN NEB/KS BORDER AREA...AND ANOTHER EXTENDING
SOUTHWESTWARD INTO NORTHEAST NEB...AND HELPING DRIVE THE ONGOING
STRONG TO SEVERE CONVECTION THAT IS IN/NEAR THE EXTREME NORTHEAST
EDGES OF THE CWA AT THIS TIME. MEANWHILE IN THE LOWER LEVELS AND
PARTICULARLY SURFACE...THE LEADING EDGES OF WHAT MANY WILL
CONSIDER TO BE A WELCOMED COLD FRONT HAS ALREADY SLICED INTO
ROUGHLY THE NORTHWEST 1/3 OF THE CWA...MARKED BY A SHIFT TO NORTH-
NORTHWEST WINDS AND AT LEAST A BRIEF PERIOD OF GUSTS TO AROUND 20
MPH. MEANWHILE...A MORE LIGHT/VARIABLE TO WESTERLY WIND DIRECTION
IS IN PLACE ACROSS MUCH OF THE SOUTHEASTERN CWA AHEAD OF THE
FRONT...IN THE VICINITY OF A WEAK 1005 MILLIBAR LOW OVER NORTH
CENTRAL KS. TEMPERATURE/HEAT INDEX WISE...AS IS TYPICAL IN THIS
SITUATION THE HIGHEST TEMPS BUT LOWEST DEW POINTS ARE CONCENTRATED
AHEAD OF THE FRONT IN THE SOUTHERN CWA...WHILE SLIGHTLY LOWER
TEMPS BUT MORE OPPRESSIVE DEWPOINTS WELL INTO THE 70S ARE FOCUSED
NEAR THE FRONT ACROSS CENTRAL/NORTHEAST AREAS. THE NET RESULT IS
THAT ROUGHLY THE SOUTHERN TWO-THIRDS OF THE CWA HAS ALREADY OR
YET-WILL EXPERIENCE A FEW HOURS OF 100-105 DEWPOINTS THIS
AFTERNOON. ALTHOUGH TO MOST FOLKS THERE WILL BE VERY LITTLE
DIFFERENCE IN HEAT INDEX VALUES ACROSS MUCH OF THE CWA...THE MOST
CONCENTRATED ZONE OF ADVISORY-LEVEL VALUES THROUGH THE REST OF THE
DAY SHOULD CONCENTRATE NEAR/SOUTH OF THE STATE LINE...AND THUS
WILL JUST CONTINUE THE PREVIOUSLY-ISSUED HEAT ADVISORY HERE. AS
FOR ACTUAL AIR TEMP HIGHS THIS AFTERNOON...PARTS OF THE NORTHERN
CWA LOOKS TO FALL A BIT SHORT WITH HIGHS ONLY IN THE 80S...WHILE
MOST NEB COUNTIES SOUTH OF INTERSTATE 80 TOP OUT SOMEWHERE IN THE
90S...WHILE KS ZONES SOLIDLY REACH THE 100-105 RANGE.

LOOKING FORWARD FORECAST-WISE AND STARTING WITH THESE NEXT FEW
HOURS THROUGH ROUGHLY 00Z/7PM...WE HAVE ALREADY SEEN THE EXTREME
NORTHEAST FRINGE OF THE CWA IN THE POLK COUNTY AREA CATCH THE FAR
SOUTHWESTERN EDGE OF STRONG-SEVERE CONVECTION THAT STARTED HOURS
AGO IN NORTHERN NEB SEVERAL HOURS AGO WITH A REPORT OF GOLF BALL
SIZE HAIL. THE MILLION DOLLAR QUESTION IS TO WHAT EXTENT TO
STORMS CONTINUE BUILDING SOUTHWARD AND POSSIBLY WESTWARD WITHIN
THE CWA...OR DOES THE COMBINATION OF THE ADVANCING FRONT AND VERY
WARM MID LEVEL TEMPS EVIDENCED BY 700MB TEMPS ON THE ORDER OF
14-16C CONTINUE TO KEEP THE VAST MAJORITY OF THE CWA STORM-FREE.
ALTHOUGH THE MOST LIKELY SCENARIO PER VARIOUS SHORT TERM MODELS IS
TO KEEP MOST CONVECTION LATE THIS AFTERNOON/EARLY THIS EVENING
WITHIN THE EASTERN ONE- THIRD OF THE CWA...HAVE OPTED TO KEEP A 20
PERCENT SLIGHT POP ACROSS MOST OF THE CWA AT SOME POINT LATE THIS
AFTERNOON INTO THIS EVENING...AS DESPITE THE STRONG CAP THE
ENVIRONMENT IS ACTUALLY FAIRLY VOLATILE FOR THIS TIME OF YEAR
INSTABILITY/SHEAR WISE...WITH LATEST HOURLY MESOSCALE ANALYSIS
SUGGESTING MIXED- LAYER CAPE ON THE ORDER OF 2500-4000 J/KG IN THE
PRESENCE OF 30-40 KNOTS OF 0-6 KM DEEP LAYER SHEAR WITHIN THE
NORTHERN HALF OF THE CWA.

TURNING TO THIS EVENING/TONIGHT POST-00Z/7PM...THE MAJORITY OF
HIGHER/RES SHORT TERM MODELS SUCH AS THE RAP/HRRR SUGGEST THAT ANY
RISK FOR STRONG-SEVERE STORMS WILL PROBABLY BE CONFINED TO ROUGHLY
THE SOUTHERN ONE-THIRD OF THE CWA BY THEN...BUT JUST IN CASE HAVE
KEPT A 20 POP GOING THROUGH 03Z/10 PM FOR ALL BUT THE FAR NORTHERN
CWA...BEFORE GRADUALLY ENDING SLIGHT STORM CHANCES FROM NORTH-TO-
SOUTH AS THE NIGHT WEARS ON. IN THE MID-UPPER LEVELS TONIGHT...THE
LOCAL FLOW ALOFT REMAINS FAIRLY STRONG AS THE AFOREMENTIONED
SEASONABLY STRONG CLOSED LOW REACHES THE DULUTH MN AREA BY
12Z/7AM. PER THE 18Z NAM...EVEN ELEVATED INSTABILITY STEADILY
FADES AWAY FROM NORTH-TO-SOUTH AS THE NIGHT GOES ON AS DRIER AIR
FILTERS IN. THIS DRIER/MORE COMFORTABLE AIR WILL ALSO BE REALIZED
AT THE SURFACE AS STEADY NORTHERLY BREEZES OF 5-15 MPH CONTINUE
THROUGH THE NIGHT. BY NIGHTS END...DEWPOINTS SHOULD BE WELL DOWN
IN THE 50S ACROSS MOST OF THE CWA...WITH SOME 60S POSSIBLY HOLDING
ON FAR SOUTH. TEMP-WISE...NUDGED DOWN LOWS SLIGHTLY FROM PREVIOUS
FORECAST...AIMING FOR A RANGE FROM NEAR 60 NORTH TO MID-UPPER 60S
SOUTH.

FOR THE SUNDAY DAYTIME HOURS...DESPITE THE POSSIBILITY OF SOME
ENHANCED MID LEVEL CLOUD COVER DEVELOPING WITHIN MAINLY THE
SOUTHWESTERN 1/3 OF THE CWA...NEARLY ALL DETERMINISTIC/HIGHER-RES
MODELS KEEP THEIR RESPECTIVE QPF/REFLECTIVITY AT LEAST SLIGHTLY
SOUTHWEST OF THE SOUTHWESTERN FRINGES OF THE CWA. AS A RESULT...AM
ADVERTISING A DRY...MOSTLY SUNNY AND LEGITIMATELY COOLER DAY CWA-
WIDE...ALTHOUGH MAY HAVE TO WATCH THOSE FAR SOUTHWESTERN FRINGES
FOR AT LEAST A PASSING SPRINKLE POTENTIAL. IN THE MID-UPPER
LEVELS...THE STRONG GREAT LAKES DISTURBANCE REACHES THE MI/IL/IN
BORDER AREA BY 00Z/7PM...WHILE AT THE SURFACE...AN EXPANSIVE HIGH
CENTERED OVER SOUTH CENTRAL CANADA WILL CONTINUE TO RESULT IN
NORTHERLY BREEZES CWA-WIDE. INCREASED THESE SPEEDS SLIGHTLY...WITH
SUSTAINED SPEEDS LIKELY 15-20 WITH GUSTS 20-25 MPH FOR MUCH OF
THE DAY ESPECIALLY WITHIN THE NORTHEAST 1/2 OF THE CWA...AND ONLY
SLIGHTLY WEAKER SOUTHWEST. ALTHOUGH THIS FRONT IS CERTAINLY NOT
USHERING IN TEMPS AS COOL AS THE BIG FRONT EARLIER THIS MONTH...WE
ARE STILL TALKING HIGHS AT LEAST 5-10 DEGREES COOLER THAN TODAY ON
SUNDAY...AND DEWPOINTS MUCH LOWER ONLY IN THE 50S. MADE VERY
LITTLE CHANGE TO HIGHS...AIMING FOR A RANGE FROM LOW-MID 80S
NORTH TO MAINLY UPPER 80S IN KS ZONES.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT JUL 26 2014

IN A PATTERN CHANGE...LOOK FOR COOLER TEMPERATURES DURING THE
EXTENDED PERIODS.

AN UPPER LOW PRESSURE SYSTEM WILL TRANSLATE SOUTHEAST THROUGH THE
OHIO VALLEY REGION LATE SUNDAY DEEPENING THE UPPER TROUGH ACROSS
FROM THE EASTERN PLAINS TO THE EASTERN CONUS.  WHILE TO THE WEST...
THE UPPER RIDGE AXIS RETROGRADES AND BUILDS OVER THE ROCKIES.
COOLER AIR WILL BACK INTO OUR REGION FROM THE EAST...AND IN THE
COOLER...DRIER AIRMASS...WE WILL SEE ANOTHER REPRIEVE FROM THE
SUMMER HEAT. H85 AVERAGE IN THE MID TEENS THROUGH THE WORKWEEK WHICH
WILL RESULT IN DAYTIME MAX TEMPS MAINLY IN THE LOWER 80S.  SFC DPS
DROP INTO THE 50S AT TIMES AND NIGHT TIME TEMPS SHOULD RANGE FROM
THE MID 50S TO THE LOW/MID 60S.

FOR PRECIPITATION CHANCES...HAVE KEPT THE FORECAST DRY THROUGH
MONDAY NIGHT AND ONLY HAVE SOME BUFFER POPS IN OUR WESTERN COUNTIES
ON TUESDAY AS CONVECTION WHICH DEVELOPS IN UPSLOPE FLOW ALONG THE
HIGH PLAINS MAY TRY TO WORK EAST SOUTHEASTWARD.  BEYOND TUESDAY
CONFIDENCE IS NOT REAL HIGH FOR PCPN CHANCES ON ANY GIVEN DAY...DUE
TO UNCERTAINTY IN TIMING OF WAVES AND BOUNDARY PLACEMENT. THE BETTER
CONVECTIVE POTENTIAL LOOKS TO RESIDE ALONG THE HIGH PLAINS REGION
AIDED BY UPSLOPE FLOW AND TO OUR SOUTH IN BETTER MOISTURE.

FOR NEXT WEEKEND...THE EXTENDED MODELS DIFFER ON WHETHER THE TROUGH
WILL DEEPEN WITH THE LOW CLOSING OFF OR WHETHER THE EASTERN TROUGH
WILL WEAKEN WITH THE WESTERN RIDGE BUILDING EASTWARD.  PERSISTENCE
LOOKS TO BE THE BEST BET AT THIS TIME.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 603 PM CDT SAT JUL 26 2014

VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS.

PERIODIC CLOUDS NEAR 3000FT AGL WILL REMAIN POSSIBLE THROUGH
03Z...WITH OCCASIONAL CLOUDS NEAR 15000FT AGL ALSO POSSIBLE
THROUGH SUNDAY MORNING. THE SURFACE WIND WILL REMAIN FROM THE
NORTH FOR THE MOST PART THROUGH THE NEXT 24 HOURS...SUSTAINED AT
10-15KTS...AND ACCOMPANIED BY HIGHER GUSTS DURING THE DAY SUNDAY.
VISIBILITY RESTRICTION IS NOT EXPECTED AT EITHER TAF SITE DURING
THE TAF PERIOD.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ083>087.

KS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ005>007-017>019.

&&

$$

SHORT TERM...PFANNKUCH
LONG TERM...FAY
AVIATION...BRYANT


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