National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KLBF 090534
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1134 PM CST SAT MAR 8 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 307 PM CST SAT MAR 8 2014

FORECAST CONCERNS IN THE SHORT TERM ARE ANOMALOUSLY WARM HIGH
TEMPERATURES FOR SUNDAY AND THE ASSOCIATED RISK OF LARGE FIRE SPREAD
AS LOWER TROPOSPHERIC MOISTURE WILL BE SPARSE.

MODELS REMAIN IN GOOD AGREEMENT REGARDING THE OVERALL SYNOPTIC
PATTERN IN THE NEAR TERM...TRANSITORY SHORTWAVE RIDGING WILL
CONTINUE TO BUILD ATOP THE CENTRAL AND NORTHERN PLAINS ON SUNDAY AS
A SHORTWAVE ADVANCES SOUTH OF THE RIO GRANDE RIVER INTO MEXICO AND
ANOTHER TROUGH CLOSES IN ON THE PACIFIC NORTHWEST.  THE
CENTRAL/NORTHERN PLAINS THERMAL RIDGE WILL BE MAXIMIZED ATOP WESTERN
NEBRASKA BY 00Z MONDAY...WITH H85 TEMPERATURES RISING AOA 15C FOR
OUR WESTERN AND SOUTHWEST ZONES BY LATE AFTERNOON.  NOW THE DEGREE
OF MIXING WILL DICTATE HOW WARM WE GET...BUT IF THE ATMOSPHERE
RESPONDS SIMILAR TO THAT OF TODAY...WE SHOULD HAVE NO TROUBLE
REACHING INTO THE MID TO UPPER 60S FOR MUCH OF THE REGION WITH LOWER
70S POSSIBLE SOUTH OF I80.   PROXIMITY SOUNDINGS INDICATES THAT MOST
LOCATIONS SHOULD MIX AT OR NEAR H85...AIDED BY A WESTERLY
DOWNSLOPING COMPONENT TO THE LOWER TROPOSPHERIC WIND.  HOWEVER THE
08.12Z NAM GUIDANCE WAS DEEMED TO BE SIGNIFICANTLY UNDERESTIMATING
THE AMOUNT OF MIXING SUNDAY AFTERNOON FOR MANY LOCATIONS ACROSS THE
CWA...THUS THE FORECAST WAS TRENDED TOWARD THE DRIER GFS/EC AND MORE
SPECIFICALLY THE HIRES ARW.  REGARDLESS...ALL THESE MODELS TEND TO
STRUGGLE WITH TEMPS AND RH WHEN DOWNSLOPING WESTERLY WIND IS
PRESENT...SO THESE VALUES MAY NOT BE LOW ENOUGH YET.

THE AIRMASS ATOP WESTERN AND NORTH CENTRAL NEBRASKA SUNDAY AFTERNOON
WILL BE QUITE DRY.  THE SHORT TERM MODELS PROJECT TD/S OF ONLY THE
MID 20S FOR MUCH THE CENTRAL SANDHILLS...WITH THE HIRES ARW
SUGGESTING A PERIOD OF MID TEEN TD/S FOR MUCH OF THE REGION SUNDAY
AFTERNOON.  UPSTREAM OBS SUPPORT LOWER SFC TD/S...WHICH THE PREVIOUS
FORECAST HAD HANDLED WELL.  IN TERMS OF WIND...THE CRAIG HIGH AND
ASSOCIATED CROSS MOUNTAIN GRADIENT IS NOT OVERLY IMPRESSIVE.  IN
FACT NUMERICAL GUIDANCE IS ONLY INDICATING WEST WINDS OF 15KTS OR
LESS. BUT AGAIN IT/S ANTICIPATED THAT THE MODELS ARE UNDERESTIMATING
THE AMOUNT OF MIXING...THUS THE AMOUNT OF MOMENTUM TRANSFER IS
SUSPECT.  AT THE LEAST...THE MODELS ARE KEYING IN A ZONE OF STRONG
/25-30KTS/ WESTERLY WIND AT 500M...STRETCHING WEST TO SOUTHEAST
ACROSS THE CENTRAL SANDHILLS THROUGH MID-AFTERNOON.  IN OPEN
AREAS...WIND GUSTS IN EXCESS OF 25 MPH WILL BE POSSIBLE ONCE
SUFFICIENT MIXING OCCURS.

GIVEN THAT CONDITIONS WILL BE FAVORABLE FOR LARGE FIRE SPREAD AND
THE FACT THAT FUELS ARE WELL CURED...A FIRE WEATHER WATCH WILL BE
ISSUED WITH THIS FORECAST PACKAGE TO INCLUDE MUCH OF WESTERN AND
NORTH CENTRAL NEBRASKA.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 307 PM CST SAT MAR 8 2014

CYCLOGENESIS IN WYOMING MONDAY WILL BEGIN SETTING THE SCENE FOR
SIGNIFICANT PRECIPITATION ON THE NORTHERN PLAINS MONDAY NIGHT AND
TUESDAY. AS FAR AS THE PATTERN IS CONCERNED...THE TRACK OF THE
CYCLONE IS FAVORABLE FOR PRECIPITATION IN CENTRAL AND NORTHERN
NEBRASKA.

MOISTURE TRANSPORT VECTORS IN THE 295-305K LAYER INDICATE MOISTURE
ADVECTION FROM THE WEST AND THE SOUTH INTO CENTRAL AND NORTHWEST
NEBRASKA MONDAY EVENING. ISENTROPIC LIFT IN THAT LAYER WILL GENERATE
RAIN IN NORTH CENTRAL NEBRASKA. THEN...AS THE CYCLONE GOES SOUTHEAST
THROUGH THE STATE...SYSTEM RELATIVE LIFT IS LIKELY AS THE COLDER AIR
COMES ACROSS WESTERN NEBRASKA. THE MOST FAVORABLE LIFT AND
SATURATION LEVELS ARE EXPECTED TO BE IN THE NORTHERN HALF OF THE
STATE. FORECAST SOUNDINGS INDICATE THAT THE MEAN TEMPERATURE IN THE
LOWEST 2KM IS ABOVE 0C INITIALLY MONDAY EVENING IT BUT SHOULD COOL
RAPIDLY AFTER MIDNIGHT...THUS ACCELERATING THE PHASE CHANGE. THE
MEDIUM RANGE MODELS ARE IN AGREEMENT WITH THE TIMING AND LOCATION OF
THE PRECIPITATION...SO OUR CONFIDENCE IS FAIRLY HIGH THAT
PRECIPITATION IN NORTHERN NEBRASKA WILL BEGIN BY EARLY TUESDAY AND
CONTINUE THROUGH THE AFTERNOON AND POSSIBLY INTO TUESDAY EVENING.

AFTER THIS...HIGH PRESSURE ALOFT BUILDS IN THE NORTHWEST AND DRY
WEATHER BECOMES DOMINANT. ALSO...FOR THE REST OF THE FORECAST...
WARMER TEMPERATURES ARE EXPECTED INTO NEXT WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1134 PM CST SAT MAR 8 2014

SCATTERED HIGH CLOUDINESS OVERNIGHT WILL BE REPLACED BY BROKEN
HIGH CLOUDINESS BY SUNDAY MORNING. LIGHT SOUTHWEST WINDS
OVERNIGHT TO BECOME 26014G23KT AFTER 15Z. WEST WINDS WILL DECOUPLE
BY 00Z/10TH.

&&

.FIRE WEATHER...
ISSUED AT 307 PM CST SAT MAR 8 2014

THE COMBINATION OF DRY FUELS...DRY AMBIENT AIRMASS...ANOMALOUSLY
WARM TEMPERATURES AND PERIODIC WESTERLY WIND GUSTS AT OR ABOVE 20
MPH WILL PROMOTE EXTREME FIRE SPREAD ACROSS PORTIONS OF WESTERN AND
NORTH CENTRAL NEBRASKA ON SUNDAY.  AT THIS TIME...FIRE ZONES
206...210...219...AND SOUTHERN PORTIONS OF 204 AND 209 HAVE THE
GREATEST OPPORTUNITY TO SEE THE CRITICAL FIRE WEATHER CONDITIONS.
THE FORECAST MODELS ARE KEYING IN ON WESTERLY DOWNSLOPING
FLOW...WHICH AT TIMES THE MODELS TEND TO STRUGGLE AS TO THE AMOUNT
OF ACTUAL DRYING/WARMING THAT OCCURS.  WITH AN ANTICIPATED INCREASED
MIXING OF THE LOWER TROPOSPHERE...THESE CRITICAL CONDITIONS SHOULD
BEGIN DURING EARLY AFTERNOON AND CONTINUE UNTIL THE ATMOSPHERE
DECOUPLES DURING THE EARLY EVENING HOURS.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR NEZ204-206-209-210-219.

&&

$$

SHORT TERM...JACOBS
LONG TERM...SPRINGER
AVIATION...ROBERG
FIRE WEATHER...JACOBS