Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 040559
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1259 AM CDT MON MAY 4 2015

.UPDATE...
ISSUED AT 954 PM CDT SUN MAY 3 2015

SURFACE ANALYSIS INDICATES A COLD FRONT MOVING SOUTHEAST ACROSS
THE AREA. AS OF 0230Z THIS FRONT WAS NOTED EXTENDING FROM JUST
SOUTH OF KJYR TO JUST NORTH KPHG. A QUIET EVENING HAS BEEN NOTED
ACROSS THE CWA AS THE FRONT ADVANCED SOUTHEAST...BUT AS OF THIS
WRITING WEAK CONVECTION IS NOTED ALONG AND JUST AHEAD OF THE
BOUNDARY...WITH DATA FROM KUEX SHOWING THIS CONVECTION MOVING INTO
PORTIONS OF PHILLIPS AND ROOKS COUNTIES IN NORTH CENTRAL KANSAS.

QUIET CONDITIONS ARE STILL EXPECTED FOR THE MOST PART THROUGH
MIDNIGHT...WITH ISOLATED TO PERHAPS SCATTERED CONVECTION
CONTINUING IN THE VICINITY OF THE FRONT ACROSS SOUTH/SOUTHEASTERN
PORTIONS OF THE CWA. AS A RESULT...WENT AHEAD WITH ~20% POPS
ACROSS OUR SOUTH/SOUTHEAST THROUGH THE NEXT FEW HOURS. WENT AHEAD
AND KEPT THE POPS AS INHERITED FROM THE DAY SHIFT FOR 06-12Z
MONDAY...WHICH PROVIDES CHANCES FOR MEASURABLE PRECIPITATION
ACROSS THE ENTIRE CWA. THAT SAID...IT IS WORTH MENTIONING THAT
CONFIDENCE REGARDING PRECIPITATION PRODUCTION IS MUCH HIGHER
ACROSS OUR SOUTH/SOUTHEAST IN THE VICINITY OF THE AFOREMENTIONED
BOUNDARY.

THE SEVERE WEATHER THREAT FOR THE REST OF TONIGHT SEEMS VERY
LIMITED ACROSS OUR CWA...BUT IT IS WORTH MENTIONING THAT THE NAM
DOES SUGGEST PARCELS ASCENDING FROM AROUND 800MB...AGAIN PRIMARILY
ACROSS OUR SOUTH/SOUTHEAST...COULD HAVE ~700J/KG OF POTENTIAL
ENERGY AND 25-30KTS OF DEEP-LAYER BULK SHEAR TO WORK WITH THROUGH
THE EARLY MORNING HOURS ON MONDAY. GIVEN THIS...OPTED TO PLAY IT
SAFE AND MAINTAIN A MENTION OF QUARTER-SIZE HAIL IN THE HWO FOR
LOCATIONS GENERALLY ALONG AND SOUTHEAST OF A LINE FROM ALMA TO
GENEVA.

THE REMAINDER OF THE FORECAST REMAINS IN GREAT SHAPE...WITH ONLY
MINOR TWEAKS MADE TO HOURLY TEMPERATURE...DEW POINT AND SKY GRIDS
TO ACCOUNT FOR CURRENT CONDITIONS.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 416 PM CDT SUN MAY 3 2015

NEEDLESS TO SAY...ITS BEEN A SOMEWHAT FRUSTRATING DAY TRYING TO
GET A HANDLE ON THE VARIOUS COMPLEXITIES OF THESE NEXT 36
HOURS...AS ALTHOUGH AT LEAST A MARGINAL TO SLIGHT RISK OF SEVERE
THUNDERSTORMS EXISTS BOTH LATE THIS AFTERNOON INTO TONIGHT AND
AGAIN MONDAY AFTERNOON INTO MONDAY NIGHT...THE VARIOUS MESOSCALE
COMPLEXITIES OF THE SITUATION MAKE IT DIFFICULT TO DISCERN JUST
HOW WIDESPREAD (OR NOT) THE COVERAGE OF SHOWERS/STORMS AND SEVERE
WEATHER COULD BE.

STARTING WITH A QUICK LOOK AT THE HERE AND NOW AS OF 21Z/4PM...THE
FIRST AND THUS FAR ONLY NEW THUNDERSTORM DEVELOPMENT OF THE MID-
LATE AFTERNOON IS UNDERWAY IN THE FAR NORTHEAST CWA NEAR SILVER
CREEK. THIS STORM IS DEVELOPING IN THE VICINITY OF A WEAK SURFACE
LOW OF AROUND 1006 MILLIBARS...AND ALONG A MODESTLY-STRONG (FOR
MAY ANYWAY) SURFACE COLD FRONT CURRENTLY INVADING THE NORTHWESTERN
1/2 OF THE CWA. COMPARED TO EXPECTATIONS OF 24 AND EVEN 12 HOURS
AGO...SURFACE WINDS TODAY ENDED UP FEATURING MUCH MORE OF A
WESTERLY VERSUS SOUTHERLY COMPONENT...WHICH HAS ALLOWED DEWPOINTS
TO MIX DOWN WELL INTO THE 40S OR EVEN UPPER 30S IN SOME
AREAS...WHILE ALLOWING TEMPERATURES TO SOAR TO RECORD OR NEAR-
RECORD LEVELS IN THE UPPER 80S-LOW 90S IN MOST PLACES (HASTINGS
ALREADY BROKE THEIR MAY 3RD RECORD OF 89). LATEST VISIBLE
SATELLITE IMAGERY CONFIRMS THAT THE MOST ROBUST...HIGH-BASED
CUMULUS FIELD AND DEVELOPING CONVECTION IS FOCUSED WITHIN THE FAR
NORTHEAST CWA IN CLOSEST PROXIMITY TO THE BETTER LOW-LEVEL
MOISTURE RESIDING OVER EASTERN NEBRASKA...WITH MORE SHALLOW CU
DEVELOPMENT TRAILING WELL OFF WEST INTO THE WESTERN CWA.

NOW LOOKING AHEAD FORECAST WISE:

LATE THIS AFTERNOON/TONIGHT: AS EVIDENCED WITH WHAT HAPPENED LAST
EVENING WITH THE GREATER-THAN-EXPECTED COVERAGE OF STRONG TO
SEVERE STORMS IN THE NORTHEAST CWA...THIS PATTERN DOES NOT YIELD
HIGH CONFIDENCE IN THE DETAILS...EVEN 6 HOURS IN ADVANCE.
HOWEVER...IN VERY GENERAL TERMS...EXPECT AT LEAST AN ISOLATED RISK
FOR MARGINALLY SEVERE STORMS TO EXIST THROUGH THE ENTIRE LATE
AFTERNOON/EVENING HOURS...INITIALLY MAINLY WITHIN THE NORTHERN CWA
IN CLOSEST PROXIMITY TO THE SURFACE FRONT IN AN ENVIRONMENT
CHARACTERIZED BY AROUND 1000 J/KG MIXED LAYER CAPE BUT ONLY FAIRLY
WEAK DEEP LAYER SHEAR AROUND 20KT. THUS AM MAINLY EXPECTING PULSY
MULTICELL UPDRAFTS WITH THE POTENTIAL FOR HAIL UP TO AROUND
QUARTERS...BUT WITH A POSSIBLY ENHANCED WIND RISK GIVEN THE VERY
DEEPLY MIXED/INVERTED V SOUNDINGS AS EVIDENCED BY AN IMPRESSIVE
40-50 DEGREE SPREAD BETWEEN THE SURFACE TEMP/DEWPOINT AHEAD OF THE
COLD FRONT. LATER IN THE EVENING...THERE ARE SUGGESTIONS THAT A
POTENTIALLY SEPARATE AREA OF STRONG-SEVERE STORMS COULD FIRE UP
MAINLY WITHIN COUNTIES SOUTH OF INTERSTATE 80 (INCLUDING KS ZONES)
AS A MODEST NOCTURNAL LOW LEVEL JET INCREASES AND ENHANCES
CONVERGENCE ALONG A SLIGHTLY ELEVATED FRONTAL ZONE. THUS HAVE
FOCUSED THE HIGHEST POPS WITHIN THE SOUTHERN HALF OF THE AREA
AFTER DARK. NOTHING IS A GUARANTEE THOUGH IN THIS PATTERN...AND
NOT EVERYBODY WILL SEE STRONG-SEVERE STORMS. WHILE THE PRIMARY
SEVERE THREAT SHOULD END BY MIDNIGHT...CANNOT RULE OUT A FEW
STRONGER STORMS LINGERING LATE INTO THE NIGHT. AT THE
SURFACE...THE SOMEWHAT NOTICEABLE COLD FRONT WILL GRADUALLY INVADE
THE CWA FROM NORTH TO SOUTH...WITH A STEADY NORTH-NORTHEAST BREEZE
SETTLING IN BEHIND IT. LOW TEMPS TONIGHT AIMED SOMEWHERE IN THE
50S.

MONDAY DAYTIME/NIGHT: OBVIOUSLY GIVEN THE UNCERTAINTIES OF JUST
THESE NEXT 6-12 HOURS...ITS TOUGH TO FEEL TOO CONFIDENT ABOUT THIS
PERIOD. HOWEVER...IN GENERAL...EXPECT THERE TO BE A BIT GREATER
POTENTIAL THAN THESE PAST FEW MORNINGS FOR AT LEAST SCATTERED
SHOWER/NON-SEVERE STORM ACTIVITY TO LINGER WELL INTO THE DAYLIGHT
HOURS. THERE WILL ALSO BE CONSIDERABLE CLOUD COVER (INCLUDING SOME
LOW STRATUS) BEHIND THE SURFACE FRONT THAT SHOULD GENERALLY BE
STALLED OUT IN SOME TYPE OF WEST-EAST FASHION WITHIN THE SOUTHERN
HALF OF THE CWA. AS FLOW ALOFT TURNS MORE SOUTHWESTERLY AND A WEAK
SURFACE LOW STARTS TO FORM ALONG THIS FRONT...IT MAY EVEN TRY
LIFTING BACK NORTH A BIT AS THE DAY WEARS ON. ASSUMING SOME BREAKS
IN CLOUD COVER...SOME HEALTHY INSTABILITY ON THE ORDER OF
1000-2000 J/KG COULD BUILD ALONG/SOUTH OF THIS BOUNDARY...IN THE
PRESENCE OF AT LEAST 30-40KT OF DEEP LAYER SHEAR. IN THEORY...THIS
COULD YIELD A MORE ROBUST SEVERE WEATHER THREAT THAN TODAY`S SETUP
EXCEPT THIS TIME LIKELY TO BE MAINLY NEAR/SOUTH OF THE STATE
LINE...WITH LESSER RISK FARTHER NORTH INTO THE CLOUDY/COOLER AIR
NORTH OF THE BOUNDARY. WILL LET UPCOMING NIGHT SHIFT SHED MORE
LIGHT ON THE POTENTIAL MAGNITUDE OF SEVERE THREAT FOR MONDAY
AFTERNOON/EVENING...BUT THE POTENTIAL IS THERE FOR A BUSY SEVERAL
HOURS PER MODELS SUCH AS THE 18Z NAM. WITH THE FRONT AND PLENTIFUL
CLOUDS LIKELY TO BE DRAPED ACROSS THE AREA...THE HIGH TEMP
FORECAST FOR MONDAY IS VERY CHALLENGING...BUT HAVE TAKEN A STAB
AIMING FOR A RANGE FROM ONLY LOW 60S IN FAR NORTHERN/WEST-CENTRAL
COUNTIES...AROUND 70 IN THE TRI-CITIES...AND UPPER 70S/LOW 80S
NEAR AND SOUTH OF THE STATE LINE. THESE HIGHS COULD EASILY BUST BY
5+ DEGREES THOUGH DEPENDING ON FRONTAL POSITIONING AND DEGREE OF
CLOUD COVER. SO MANY UNCERTAINTIES IN THIS COMPLEX PATTERN...

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 PM CDT SUN MAY 3 2015

CHALLENGES IN THE MID AND LONG TERM PERIODS CONTINUE TO FOCUS ON
NUMEROUS CHANCES FOR THUNDERSTORMS...SEVERITY OR LACK THEREOF. MODEL
SOLUTIONS SUGGEST A FAIRLY WET PATTERN OVERALL WITH QPF GENERATED
ACROSS AT LEAST A PORTION OF THE AREA DURING EACH PERIOD. THUS
LEAVING ZERO DRY PERIODS IN THE LONG TERM...EVEN THOUGH SUCH
WIDESPREAD PRECIPITATION EVERY DAY IS CERTAINLY NOT EXPECTED.

AT THE SYNOPTIC LEVEL BY THE BEGINNING OF THE LONG TERM....NEARLY
ZONAL FLOW IS REALIZED IN THE UPPER LEVELS ACROSS THE EASTERN
SEABOARD. A WEAK UPPER LEVEL LOW PRESSURE SYSTEM IS SLIDING EAST
ACROSS THE DESERT SOUTHWEST...WHILE A DEEPENING UPPER LEVEL LOW IS
DROPPING INTO THE PACIFIC NORTHWEST. THE CENTRAL PLAINS REMAIN
FLANKED BY BOTH A SOUTHERN AND NORTHERN JET STREAM...WHILE PLENTY
OF LOW LEVEL MOISTURE IS SURGING NORTHWARD INTO THE PLAINS FROM THE
GULF.

THE SOUTHWESTERN LOW PRESSURE SYSTEM STEADILY CREEPS TOWARD THE
REGION BY TUESDAY MORNING...WHICH HELPS LIFT THE WARM FRONTAL
BOUNDARY NORTH OF THE FORECAST AREA. OF THE LONG TERM...THIS TUESDAY
MORNING PERIOD "SHOULD" BE THE DRIEST OF THE BUNCH...ALTHOUGH AT
THIS POINT ANYTHING COULD HAPPEN. BY AFTERNOON...WARM AIR ADVECTION
WILL INTRODUCE CHANCES FOR AFTERNOON THUNDERSTORMS...ALTHOUGH LITTLE
INSTABILITY EXITS FOR A SEVERE POTENTIAL.

WEDNESDAY REMAINS A DIFFERENT STORY ENTIRELY AS THE UPPER LEVEL
SYSTEM IS NOW NEARLY ON TOP OF THE CENTRAL PLAINS...ALBEIT SLIGHTLY
WEAKER AS IT MOVES EASTWARD. AT THE SURFACE...LOW PRESSURE ALONG THE
FRONT RANGE CONTINUES TO DRIVE SOUTHERLY WINDS...AND THUS MOISTURE
INTO THE REGION. INSTABILITY IS MUCH HIGHER BY THE AFTERNOON WITH
1400 J/KG OF CAPE ACROSS NORTH CENTRAL KANSAS AND SOUTH OF
INTERSTATE 80 IN NEBRASKA. INCREASED BULK SHEAR VALUES OF 45 KTS ARE
EVIDENT ACROSS NORTH CENTRAL KANSAS IN THE 0 TO 6 KM LAYER...WHILE
30 TO 35 KTS ARE EXPECTED IN THE 0 TO 1 KM LAYER...PER THE GFS
SOLUTION. ALTHOUGH OTHER MODEL SOLUTIONS ARE NOT QUITE THE MAGNITUDE
AS THE GFS...RIGHT NOW WEDNESDAY AFTERNOON IS DEFINITELY THE
TIMEFRAME TO WATCH IN THE EXTENDED PERIOD.

FOR THE REMAINDER OF THE LONG TERM PERIOD...THE DOOR TO THE GULF
MOISTURE REMAINS WIDE OPEN. ALTHOUGH THE WEAKER UPPER LEVEL SYSTEM
CONTINUES TO TRUDGE NORTH OF THE PLAINS...THE DEEPENING SYSTEM
ACROSS THE PACIFIC NORTHWEST WILL CONTINUE TO SWING EAST ACROSS THE
ROCKIES. OUT AHEAD OF THE PARENT SYSTEM...NUMEROUS SHORTWAVES WILL
SLIDE ACROSS THE PLAINS BEFORE THE UPPER LEVEL LOW FINALLY SLIDES
INTO THE PLAINS BY THE WEEKEND. AT THE SURFACE...A COLD FRONT WILL
SLIDE INTO THE REGION ON THURSDAY...STALLING ACROSS THE SOUTHEAST.
ALTHOUGH MODELS SEEM TO DRY OUT DURING THE DAY ON
THURSDAY...ESPECIALLY ACROSS THE WEST...STORMS COULD CERTAINLY FIRE
ALONG THE BOUNDARY. THUS KEPT THUNDERSTORM CHANCES AT LEAST FOR THE
SOUTHEAST ON THURSDAY. THE MEANDERING BOUNDARY WILL SHIFT JUST SOUTH
OF THE AREA FRIDAY...WHICH COULD DRY OUT NORTHERN PORTIONS OF THE
FORECAST AREA...ALTHOUGH MODELS ARE STILL SHOWING QPF AS WARM AIR
OVERRUNS THE BOUNDARY. THE MAIN UPPER LEVEL SYSTEM SWINGS INTO THE
AREA THIS WEEKEND...WHICH RESULTS IN PROBABLY THE BEST CHANCE FOR
PRECIPITATION IN THE LONG TERM ON SATURDAY. ALTHOUGH KEEP IN MIND
THIS IS LOOKING AT DAY 7 AND MANY THINGS CAN CHANGE.

&&

.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1256 AM CDT MON MAY 4 2015

AS A FRONT STALLS WELL SOUTH OF THE TERMINALS...A STRATUS DECK IS
EXPECTED TO MOVE IN AND SOCK US IN WITH SKY COVER. THERE COULD BE
SOME ELEVATED THUNDERSTORMS...ESPECIALLY TOWARD MONDAY
AFTERNOON/EVENING...BUT COVERAGE IS UNCERTAIN. VISIBILITY COULD BE
SIGNIFICANTLY LESS IN A THUNDERSTORM...BUT SINCE PREDICTABILITY IS
SO LOW...ANYTHING SPECIFIC HAS BEEN LEFT OUT OF THIS
FORECAST.

&&

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

$$

UPDATE...BRYANT
SHORT TERM...PFANNKUCH
LONG TERM...SALTZMAN
AVIATION...HEINLEIN



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