Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KLBF 190848
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
348 AM CDT SUN OCT 19 2014

.SYNOPSIS...
ISSUED AT 348 AM CDT SUN OCT 19 2014

SURFACE ANALYSIS BETRAYED GENERAL TROUGHINESS ACROSS THE HIGH PLAINS
WITH WEAK LOW PRESSURE CENTERS IN SOUTHEAST WYOMING AND SOUTHEAST
COLORADO. A WEAK BOUNDARY WAS DISCERNIBLE FROM SOUTH CENTRAL NORTH
DAKOTA THROUGH SOUTHEAST WYOMING TO SOUTHEAST COLORADO...BUT THE
TEMPERATURE DISCONTINUITY ACROSS IT WAS MINIMAL. HIGH PRESSURE WAS
THE DOMINANT FEATURE ACROSS THE INTER-MOUNTAIN REGION FROM NORTHERN
IDAHO TO NORTHERN UTAH.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CDT SUN OCT 19 2014

SOUTHERLY FLOW ALONG THE HIGH PLAINS TROUGH WILL BRING UNSEASONABLY
WARM TEMPERATURES TO WESTERN NEBRASKA. WIND IS LIKELY TO SHIFT TO
THE NORTH AS THE TROUGH MAKES ITS WAY EASTWARD WITH LITTLE OR NO
INFLUENCE ON THE WARM TEMPERATURES. WIND WILL BECOME VERY LIGHT THIS
EVENING...THUS ALLOWING TEMPERATURES TO FALL INTO THE MID 30S TO
LOWER 40S TONIGHT.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 348 AM CDT SUN OCT 19 2014

FORECAST CONCERNS THROUGH THIS PERIOD ARE WITH TEMPERATURES MONDAY
AND TUESDAY...THEN WITH RAIN CHANCES WEDNESDAY AND WEDNESDAY
NIGHT.

MODELS ARE IN DECENT AGREEMENT THROUGH THURSDAY...WHEN THERE IS
SOME DISCONTINUITY ON THE NEXT SYSTEM COMING ONSHORE INTO THE
PACIFIC COAST...AND THUS WITH THE STRENGTH OF THE RIDGING
IMPACTING THE PLAINS FOR LATE IN THE WEEK.

BEGINNING ON MONDAY...THE UPPER LEVEL RIDGE AXIS WILL BE DIRECTLY
OVER THE PLAINS AND AS A SURFACE HIGH LOCATED OVER THE FORECAST
AREA MONDAY MORNING AT 12Z DRIFTS EAST THROUGH THE DAY WINDS WILL
SWITCH AROUND TO THE SOUTH. 850MB TEMPERATURES INCREASE A FEW
DEGREES C FROM WHAT WILL BE SEEN ON SUNDAY. NO CLOUD COVER IS
EXPECTED FOR MONDAY AS VERY DRY AIR WILL BE IN PLACE SO SUNNY
SKIES SHOULD PROMOTE GOOD MIXING OF THE BOUNDARY LAYER TO AROUND
850-800MB. THIS WOULD PUT SURFACE TEMPERATURES IN THE 70S FOR THE
ENTIRE FORECAST AREA. EVEN WITH THE WARMER AIR IN PLACE
ALOFT...DRY AIR AND LIGHT WINDS MONDAY NIGHT INTO TUESDAY SHOULD
CAUSE GOOD RADIATIONAL COOLING TO DROP LOWS DOWN INTO THE UPPER
30S TO LOW 40S. THAT BEING SAID...NOT LOOKING FOR WINDS TO
COMPLETELY DROP OFF TO CALM SO THE POTENTIAL COULD BE COLDER IF
WINDS DO IN FACT GO CALM.

A LITTLE WRENCH IN THE FORECAST FOR MONDAY NIGHT INTO TUESDAY IS
IF FOG OR STRATUS WILL DEVELOP OVER WESTERN NEBRASKA INTO THE
PANHANDLE. BOTH THE NAM AND GFS SHOW MOISTURE BEING PULLED NORTH
INTO NEBRASKA IN THE SOUTHERLY LOW LEVEL FLOW AND WITH THE WINDS
THAT ARE EXPECTED WOULD THINK IT WOULD BE IN THE FORM OF A STRATUS
DECK. IF THESE CLOUDS DO DEVELOP...IT COULD IMPACT TUESDAY MORNING
LOWS...AND IF THEY ARE SLOW TO BREAK UP COULD THEN IMPACT
TUESDAY/S HIGHS. BELIEVE THIS IS THE REASONING FOR THE 10 DEGREE
DIFFERENCE IN THE STATISTICAL GUIDANCE FROM THE MET AND MAV
PRODUCTS AS THEY VARY FROM 70 TO 80 F AT KLBF FOR TUESDAY. IF
THERE IS NO CLOUDS OR IF THEY BREAK UP QUICKLY /WHILE THE MODELS
DO SHOW THEM STICKING AROUND INTO THE AFTERNOON/ TUESDAY SHOULD BE
QUITE WARM AS THE RIDGE STARTS TO BREAK DOWN BRINGING THE WARMEST
TEMPERATURES ALOFT /NEARING 20C OVER SOUTHWEST NEBRASKA/ AND
BREEZY SOUTHERLY WINDS. AGAIN...GOOD MIXING IS EXPECTED FOR
TUESDAY /PENDING THE CLOUD COVER ISSUE/ SO SHOULD EASILY BE ABLE
TO MIX TO THE 850MB LEVEL AND WITH MODELS SHOWING WINDS OF 30 TO
40KTS AT THAT LEVEL...IT WILL BE QUITE A WINDY DAY.

A FEW OF THE MODEL SOLUTIONS HAVE SPED UP A BIT WITH THE ONSET UP
RAIN LATE TUESDAY NIGHT/WEDNESDAY MORNING. THE NAM REMAINS DRY
UNTIL THE DAYTIME HOURS AS IT IS SLOWER WITH THE SURFACE
TROUGH/COLD FRONT MOVING INTO THE HIGH PLAINS. BOTH THE GFS AND
ECMWF HOWEVER HAVE THE FRONT FROM ABOUT KIML TO KTIF TO KICR BY
12Z. THE UPPER LEVEL TROUGH THEN PASSES ACROSS NEBRASKA DURING THE
DAY WEDNESDAY AND THEN QUICKLY PUSHES EAST OF THE AREA ON
THURSDAY. AHEAD OF THE SYSTEM AS HAS BEEN ADVERTISED...MOISTURE
WILL INCREASE DRAMATICALLY AS PRECIPITABLE WATER VALUES INCREASE
TO OVER AN INCH IN PLACES...WHICH IS OVER 2 STANDARD DEVIATIONS
ABOVE NORMAL. WITH THE INFLUX OF MOISTURE...WILL BE LOOKING TO
BUILD SOME INSTABILITY ACROSS THE FORECAST AREA DURING THE DAY
WEDNESDAY. THE INSTABILITY LOOKS QUITE MEAGER THOUGH...WITH LESS
THAN 700 J/KG AND SOUNDINGS SHOWING VERY MINIMAL CAPE THINKING
THAT THERE WILL BE SOME THUNDER EMBEDDED IN THE SHOWERS AS THEY
MOVE THROUGH THE AREA...BUT NOTHING SUBSTANTIAL. THE MAIN PERIOD
FOR PRECIPITATION WILL BE DURING THE DAY WEDNESDAY...WHICH HASN/T
CHANGED...BUT MODIFICATIONS HAVE BEEN MADE TO ACCOUNT FOR SOME
TIMING DIFFERENCES FOR THE BEGINNING AND ENDING OF THE RAIN. THE
RAIN SHOULD BE OUT OF THE LOCAL FORECAST AREA BY 12Z THURSDAY AS
IS IN THE FORECAST.

THEN MOVING INTO THE LATTER PART OF THE WEEK...THE SHORTWAVE
TROUGH THAT MOVES THROUGH HERE ON WEDNESDAY WILL DIG SOUTH INTO
EASTERN TEXAS THEN MAY SLOWLY TRAVEL EAST ACROSS THE DEEP SOUTH.
IN THE MEANTIME...RIDGING ALOFT BUILDS BACK IN OVER THE CENTRAL
PART OF THE COUNTRY AS ANOTHER SYSTEM MOVES ONSHORE FROM THE
PACIFIC. THIS SHOULD LEAD TO ANOTHER WARMING TREND AND ABOVE
NORMAL TEMPERATURES GOING INTO NEXT WEEKEND. JUST HOW WARM IT GETS
WILL DEPEND ON THE STRENGTH OF THE RIDGE WHICH AT THIS POINT
VARIES BETWEEN THE GFS AND THE ECMWF. EITHER WAY THOUGH...LOOKING
AT HIGHS AGAIN IN THE 70S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1145 PM CDT SAT OCT 18 2014

OTHER THAN SOME SCATTERED HIGH CLOUDINESS OVERNIGHT...CLEAR SKIES
WILL PREVAIL ON SUNDAY AND SUNDAY EVENING. WINDS WILL BE FROM THE
SOUTH AT AROUND 10 KTS OVERNIGHT...SHIFTING TO THE NORTH AT 10 KTS
FOR SUNDAY AND SUNDAY EVENING.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...BROOKS
AVIATION...CLB









USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.