Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 112344
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
644 PM CDT FRI APR 11 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 410 PM CDT FRI APR 11 2014

GIVEN THAT THIS DISCUSSION ONLY CONCERNS WEATHER THROUGH 00Z/7PM
SATURDAY EVENING...WANT TO STATE OFF THE TOP THAT ANY THUNDERSTORM
AND POTENTIAL SEVERE WEATHER POSSIBILITY FOR SATURDAY APPEARS TO
BE TRENDING MORE AND MORE TOWARD THE EVENING/OVERNIGHT PERIOD AS
DESCRIBED IN THE LONG TERM SECTION BELOW. AS A RESULT...WITH THE
POSSIBLE EXCEPTION OF LATE SATURDAY AFTERNOON IN SOUTHERN
AREAS...THESE NEXT 24 HOURS SHOULD BE PRETTY QUIET WEATHER-WISE
EXCEPT FOR THE ONGOING NEAR-CRITICAL FIRE DANGER ACROSS MUCH OF
THE AREA THROUGH EARLY THIS EVENING.

SPEAKING OF CURRENT WEATHER...20Z/3PM OBJECTIVE SURFACE ANALYSIS
CONFIRMS BROAD SOUTHERLY FLOW OVER THE CENTRAL PLAINS...DIRECTED
BETWEEN A HIGH CENTERED TO THE EAST OVER THE MO/IL AREA...AND A
HIGH PLAINS LEE TROUGH TO THE WEST. FORTUNATELY...SUSTAINED WIND
SPEEDS IN MOST AREAS ARE ONLY AVERAGING AROUND 15 MPH OR LESS WITH
GUSTS AT LEAST SLIGHTLY UNDER 25 MPH...WHICH IS THE ONLY THING SAVING
US FROM NEEDING A FIRE WEATHER HEADLINE FOR CRITICAL DANGER GIVEN
THAT THE RELATIVE HUMIDITY COMPONENT OF FIRE DANGER ACROSS MOST OF
THE CWA IS DOWN IN THE CRITICAL 15-25 PERCENT RANGE. ALTHOUGH THE
LOW LEVEL AIRMASS IS STILL VERY DRY LOCALLY...ITS WORTH NOTING
THAT THE LEADING EDGES OF LOW 50S DEWPOINTS ARE NOW AS CLOSE AS
FAR SOUTHERN KS. CLOUD- WISE...ALTHOUGH A BATCH OF INCREASING
HIGH CIRRUS IS STEADILY PUSHING IN FROM THE WEST AT THIS
HOUR...THE MAJORITY OF THE CWA HAS ENJOYED MOSTLY SUNNY SKIES THUS
FAR TODAY...AND HIGH TEMPS ARE HEADED INTO THE 75-79 RANGE IN MOST
AREAS. LOOKING ALOFT TO THE MID/UPPER LEVELS...WATER VAPOR
SATELLITE AND SHORT TERM MODEL DATA REVEALS BROAD...MOISTURE-
STARVED WEST-NORTHWEST FLOW ALOFT...AS THE LOCAL AREA REMAINS
ALONG THE SOUTHERN PERIPHERY OF NORTHERN STREAM FLOW WITHIN A
SPLIT UPPER-JET FLOW REGIME ACROSS THE CONUS. IN THE SOUTHERN
STREAM...THE PRIMARY LOW PRESSURE SYSTEM OF INTEREST IS A CLOSED
MID LEVEL LOW OFF THE SOUTHERN CAL COAST...WHILE IN THE NORTHERN
STREAM A LOW-AMPLITUDE SHORTWAVE IS SLIDING EAST-SOUTHEAST OUT OF
CANADA INTO THE NORTHERN MT AREA.

LOOKING FORWARD THROUGH LATE THIS AFTERNOON INTO TONIGHT...RIGHT
OFF THE BAT WE WILL OBVIOUSLY CONTINUE THE MENTION OF NEAR-
CRITICAL FIRE DANGER IN THE HAZARDOUS WEATHER OUTLOOK UNTIL RH
VALUES COME BACK SOLIDLY ABOVE 20-25 PERCENT EARLY THIS EVENING.
OTHERWISE...IN THE MID-UPPER LEVELS TONIGHT FLOW WILL GRADUALLY
TRANSITION TO WEST-SOUTHWEST...AS THE BEGINNING STAGES OF MODEST
PHASING BETWEEN THE NORTHERN/SOUTHERN STREAM FLOW GETS UNDERWAY. A
BIT LOWER IN THE ATMOSPHERE...A FAIRLY STOUT SOUTH-SOUTHWESTERLY LOW
LEVEL JET AT 850 MILLIBARS WILL RAMP UP TO SPEEDS IN THE 40-50KT
RANGE LATER TONIGHT...BUT THE PRIMARY EXIT REGION/NOSE OF THIS JET
WILL FOCUS WELL NORTHEAST OF THE CWA INTO THE SD/MN AREA...AND AS
A RESULT THE MAIN FOCUS FOR OVERNIGHT SHOWERS/STORMS SHOULD BE UP
IN THIS AREA AS WELL. ALTHOUGH CONFIDENCE IS PRETTY HIGH IN A DRY
NIGHT LOCALLY...ITS WORTH NOTING THAT THE 18Z NAM LIFTS AN AREA OF
500+ J/KG OF ELEVATED CAPE IN THE 850-700MB LAYER NORTHWARD
ACROSS THE AREA TONIGHT...BUT ALSO ACCOMPANIED BY CONSIDERABLE
CONVECTIVE INHIBITION (CIN) THAT SHOULD KEEP EVEN ROGUE/ISOLATED
SHOWERS OR WEAK STORMS AT BAY. AT THE SURFACE TONIGHT...FOLLOWING
A BRIEF LULL IN WIND SPEEDS THROUGH EARLY EVENING...EXPECT A
FAIRLY STEADY 15-20 MPH BREEZE WITH HIGHER GUSTS THROUGH MOST OF
THE NIGHT AS THE PRESSURE GRADIENT TIGHTENS A BIT AND LOW LEVEL
MIXING INCREASES UNDER THE LOW LEVEL JET. HOWEVER...TOWARD SUNRISE
A SURFACE TROUGH WILL EASE INTO NORTHWEST PARTS OF THE
CWA...RESULTING IN DECREASING BREEZES THAT BECOME MORE WESTERLY.
TEMP-WISE...MADE VERY LITTLE CHANGE TO OVERNIGHT LOWS...AIMING FOR
SEASONABLY MILD MID-50S ACROSS MOST OF THE CWA UNDER MOSTLY CLEAR
SKIES...BUT WITH SLIGHTLY COOLER VALUES AROUND 50 IN FAR
WESTERN/NORTHERN NEB ZONES WHERE BREEZES BECOME A BIT LIGHTER.

FOR THE DAYTIME HOURS SATURDAY...THE SHORT STORY IS THAT THE
MORNING THROUGH EARLY-MID AFTERNOON SHOULD REMAIN DRY ACROSS MOST
OF THE CWA...WITH THE ONLY LATE AFTERNOON POPS NOW CONSISTING OF
ONLY A SLIGHT CHANCE OF SHOWERS/STORMS FOR AREAS GENERALLY SOUTH
OF A GENEVA-PHILLIPSBURG LINE...NEAREST THE MAIN SURFACE FRONT. IN
THE BIG PICTURE ALOFT...SOUTHWEST FLOW ALOFT WILL RAMP UP A BIT AS
A PHASING OF NORTHERN/SOUTHERN STREAMS CONTINUES. ALTHOUGH THE
STRONGEST VORT MAX IN THE SOUTHERN STREAM SYSTEM WILL ONLY REACH
AZ BY LATE AFTERNOON...VARIOUS MORE-SUBTLE WAVES WILL EJECT TOWARD
THE CENTRAL PLAINS OUT AHEAD OF THE MAIN VORT ESPECIALLY DURING
THE AFTERNOON. AT THE SURFACE...A WEAK COLD FRONT WILL SETTLE INTO
THE CWA DURING THE DAY...PUSHED SOUTHWARD BY THE NORTHERN STREAM
DISTURBANCE PASSING EASTWARD NEAR THE CANADIAN BORDER. THIS FRONT
WILL RESULT IN A GRADUAL SHIFT FORM SOUTHWESTERLY...TO
NORTHERLY...TO EASTERLY BREEZES ACROSS MOST OF THE CWA DURING THE
DAY...AT SUSTAINED SPEEDS GENERALLY NO MORE THAN 10-15 MPH. WHERE
THESE NORTHEASTERLY BREEZES MEET UP WITH THE PREVAILING SOUTHERLY
BREEZES OVER MOST OF KS WILL DICTATE WHERE THE MAIN SURFACE FRONT
SETS UP DURING THE AFTERNOON...WHICH SHOULD GENERALLY EXTEND ALONG
A CENTRAL IA TO CENTRAL KS AXIS. ALTHOUGH SUSPECT MODELS SUCH AS
THE NAM MAY STILL BE OVERDOING MOISTURE RETURN AND RESULTANT
INSTABILITY...IT CURRENTLY ADVERTISES 0-1KM MIXED LAYER CAPE OF
1500-2500 J/KG BY MID-LATE AFTERNOON ACROSS MUCH OF THE SOUTHEAST
HALF OF THE CWA. HOWEVER...FORECAST SOUNDINGS CLEARLY SHOW A
FAIRLY STRONG CAP AS WELL AND DECENT CIN...WHICH ACCORDING TO
VARIOUS MODELS INCLUDING THE 12Z 4KM WRF-NMM WILL ACT TO STRONGLY
ENCOURAGE A LACK OF LOCAL THUNDERSTORM DEVELOPMENT THROUGH LATE
AFTERNOON. HOWEVER...OPTED TO LINGER JUST A SLIGHT CHANCE OF
STORMS IN THE AFOREMENTIONED SOUTHERN AREAS AFTER 21Z/4PM JUST IN
CASE THIS CAP CAN BREAK. HOWEVER...THIS SEEMS MORE LIKELY FARTHER
EAST ALONG THE FRONT INTO CENTRAL IA/POSSIBLY FAR SOUTHEAST
NEB/NORTHEAST KS. IF LATE AFTERNOON STORMS DO FORM...OBVIOUSLY
SEVERE WEATHER IS A POSSIBILITY GIVEN DEEP LAYER SHEAR AROUND
40KT...BUT AGAIN THIS IS NOT LIKELY. TEMP-WISE...MADE LITTLE
CHANGE TO PREVIOUS HIGHS OTHER THAN TO COOL THE FAR WEST/NORTHWEST
DOWN A FEW DEGREES...BUT AIMING MOST AREAS IN THE MID-UPPER 70S.
ALTHOUGH SURFACE DEWPOINTS WELL INTO THE 40S-50S SHOULD BE IN
PLACE DURING THE AFTERNOON ACROSS MOST OF THE CWA KEEPING FIRE
DANGER ON THE LOWER SIDE...ROUGHLY THE NORTHWEST 1/3 IS PROGGED TO
ONLY SEE 30S DEWPOINTS WHICH WOULD DROP RH VALUES DOWN TO AROUND
25 PERCENT...BUT STILL SAFELY ABOVE CRITICAL FIRE DANGER.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 PM CDT FRI APR 11 2014

THE PRIMARY FORECAST CONCERN WILL CENTER AROUND THE
STRONG STORM SYSTEM THAT WILL BE TRACKING ACROSS OUR FORECAST AREA
AT THE START OF THE PERIOD SATURDAY NIGHT THROUGH SUNDAY NIGHT.
SEVERE THUNDERSTORMS WILL BE POSSIBLE SATURDAY NIGHT FOLLOWED BY THE
CHANCE OF RAIN MIXING WITH SNOW BY SUNDAY AFTERNOON/SUNDAY NIGHT.
MONDAY THROUGH WEDNESDAY WILL BE DRY AND THEN A SLIGHT CHANCE OF
RAIN SHOWERS WILL RETURN TO PORTIONS OF THE FORECAST AREA BY
THURSDAY AND FRIDAY. LOW TEMPERATURES WILL FALL TO BELOW FREEZING IN
MOST AREAS SUNDAY NIGHT INTO MONDAY NIGHT. HIGHS ON MONDAY WILL
STRUGGLE TO AROUND 50 BUT EXPECT NEAR NORMAL HIGHS OF AROUND 60 TO
THE LOWER 60S FOR MOST AREAS TUESDAY THROUGH FRIDAY.

SATURDAY NIGHT...THE SURFACE BASED INSTABILITY IS CONFINED TO OUR
FAR SOUTHERN FORECAST AREA...BUT ELEVATED INSTABILITY WILL EXTEND
NORTHWARD TO ENCOMPASS MOST OF OUR FORECAST AREA. HOWEVER...MUCAPE
VALUES NORTH OF INTERSTATE 80 ARE EXPECTED TO GENERALLY BE LESS THAN
500 J/KG AND THUS WILL FORECAST THE PRIMARY SEVERE WEATHER THREAT
FOR OUR SOUTHERN FORECAST AREA WHERE INSTABILITY WILL BE
HIGHER...SOUTH OF INTERSTATE 80...WHERE MUCAPE VALUES WILL RANGE
FROM 500 TO 2000 J/KG. DEEP LAYER SHEAR (0-6 KM) WILL BE MORE THAN
SUFFICIENT FOR SEVERE WEATHER POTENTIAL AT GREATER THAN 50KTS...BUT
THE INSTABILITY WILL BE THE LIMITING FACTOR FOR SOME AREAS. A LOOK
AT MOST MODELS AND ENSEMBLES POINTS TO THE GREATEST THREAT OF SEVERE
WEATHER IN THE 10 PM TO 1 AM TIME.

SUNDAY...COLD AIR ADVECTION WILL BE ONGOING THROUGH THE DAY WITH
THE SUNDAY HIGHS LIKELY OCCURRING AT MIDNIGHT SATURDAY NIGHT WITH
TEMPERATURES THEN FALLING THROUGH THE DAY TIME HOURS. THE WIND WILL
BE NEAR ADVISORY LEVELS DUE TO THE STRONG PRESSURE GRADIENT. THE
PRECIPITATION TYPE WILL PRIMARILY BE RAIN THROUGH MOST OF THE
DAY...BUT COULD SEE A CHANGE OVER TO SNOW FROM NORTH TO SOUTH BY
LATE AFTERNOON/EVENING AS EVEN COLDER AIR WORKS IN. AM NOT EXPECTING
ANY SNOW TO ACCUMULATE AS THE SOIL TEMPERATURES ARE WARM AND THE SFC
AIR TEMPERATURES AREA ALSO EXPECTED TO BE HOVERING A FEW DEGREES
ABOVE FREEZING 33-37F...WHICH WILL MAKE ACCUMULATION DIFFICULT.
RAIN/SNOW WILL GRADUALLY COME TO AN END FROM NORTH TO SOUTH SUNDAY
NIGHT WITH TEMPERATURES FINALLY FALLING TO JUST BELOW FREEZING BY
AROUND DAWN ON MONDAY MORNING.

MONDAY...IT WILL TAKE SOME TIME TO MODERATE THE AIR MASS BEHIND THE
DEPARTING STORM SYSTEM AND EXPECT HIGHS WILL BE WELL BELOW
NORMAL...BUT IT WILL BE DRY.

TUESDAY-FRIDAY...HIGHS WILL BE BACK TO AROUND NORMAL AND MOST AREAS
WILL LIKELY BE DRY ALTHOUGH THERE ARE A FEW LOW END CHANCES OF RAIN
LATE IN THE WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 623 PM CDT FRI APR 11 2014

A BAND OF HIGH CLOUDS WILL MOVE ACRSOS THE TERMINAL THIS EVENING.
HEADING INTO TONIGHT...SOUTHERLY SFC WINDS WILL DECREASE TO AROUND
10KTS BUT ABOVE THE SFC WINDS WILL INCREASE TO 45KTS AND INCLUDED
A PERIOD OF LLVL WIND SHEAR. ALSO TONIGHT IN THE INCREASING
SOUTHERLY FLOW THERE IS THE POTENTIAL FOR STRATUS TO WORK NORTH FM
THE SOUTHERN PLAINS TOWARDS KGRI. MODELS ARE PRETTY AGRESSIVE WITH
THE LLVL MOISTURE RETURN AND CONFIDENCE IS LOW AS TO WHETHER KGRI
WILL SEE STRATUS OR NOT. HAVE KEPT CLOUDS AS SCATTERED FOR NOW.
THE LOWER CLOUD COVER IS EXPECTED TO ERODE SATURDAY AND WINDS WILL
SHIFT NORTHEASTERLY BEHIND A COLD FRONT.

&&

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

$$

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



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