FXUS65 KSLC 300945
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
245 AM MST MON NOV 30 2009

.SYNOPSIS...HIGH PRESSURE WILL BUILD INTO THE AREA TODAY AND
PERSIST THROUGH TONIGHT. A SYSTEM DROPPING THROUGH THE PLAINS WILL
SEND A DRY COLD FRONT ACROSS UTAH ON TUESDAY. 

&&

.DISCUSSION...WATER VAPOR LOOP SHOWS A RIDGE BUILDING IN FROM THE 
WESTERN CONUS AS AN UPPER LOW SINKS SOUTH FROM ARIZONA. A WAVE IS 
BEGINNING TO DEVELOP ALONG AN EASTERN PACIFIC SHEAR ZONE...NEAR 
38N/146W. 400-250MB ACARS WIND OBSERVATIONS SHOWS A 125-150KT 
ANTICYCLONICALLY CURVED JET FROM WESTERN CANADA INTO THE CENTRAL 
CONUS...WEAKENS TO 80-100KT AS IT CROSSES BACK INTO THE FOUR CORNERS 
AND SOUTHERN CALIFORNIA. 00Z 700MB ANALYSIS SHOWS A CYCLONE ACROSS 
SOUTHERN ARIZONA WITH RIDGING ACROSS THE PACIFIC NORTHWEST. 
ADVECTION HAS TURNED NEUTRAL LOCALLY WITH -2C AT KSLC WITH A NORTH 
WIND. 00Z KSLC RAOB INDICATES ABOUT 3C OF COOLING BELOW 750MB WITH 
5C OF WARMING ALOFT DURING THE PAST 24 HOURS. A WEAK INVERSION WAS 
NOTED AT 780MB WITH A STRONGER ONE DEVELOPING AT 720MB.

GOES/RUC PRECIPITABLE WATER INDICATE VALUES RANGE BETWEEN A QUARTER 
AND THIRD OF AN INCH ACROSS THE REGION.

LAST DAY OF METEOROLOGICAL FALL WILL BE QUIET WEATHER-WISE WITH HIGH 
PRESSURE BUILDING IN SURFACE AND ALOFT. LAST AIRMASS CHANGE HAS 
CLEARED OUT THE HAZE IN THE NORTHERN VALLEYS. DID GO BELOW GUIDANCE 
FOR HIGH TEMPERATURES NEAR CEDAR CITY AND THE CENTRAL/SOUTHERN 
MOUNTAINS WHERE IT HAS SNOWED RECENTLY.

A STRING OF CLEAR CALM NIGHTS WILL COMBINE WITH WARMING AT RIDGETOP 
LEVEL TO SUPPORT A STRENGTHENING INVERSION...WITH A TREND FOR 
DEGRADING AIR QUALITY INTO MID WEEK. GUIDANCE IS RUNNING COLDER WITH 
RESPECT TO THE NEXT SURGE OF COLD AIR INTO THE NORTH CENTRAL CONUS 
DURING THE MID WEEK...PROVIDING SOME HOPE THAT THERE WILL BE ENOUGH 
COLD AIR AND FLOW TO IMPROVE AIR QUALITY ONCE AGAIN.

CONFIDENCE CONTINUES TO BE LOWER THAN TYPICAL IN THE LONG RANGE 
HEADING INTO THE WEEKEND.
 
THE GFS AND CANADIAN CONTINUE TO SHOW A STRONG COLD FRONT ARRIVES 
FROM THE PACIFIC NORTHWEST LATE FRIDAY...WITH SIGNIFICANT COOLING 
ALOFT AS THE SYSTEM SPLITS AND DEEPENS OVER THE REGION LATE THIS 
WEEKEND. THE EUROPEAN DOES NOT SUPPORT THIS SOLUTION...RATHER 
SHOWING A WEAKER COLD FRONT ARRIVING LATER DURING THE WEEKEND...WITH 
TROPICAL MOISTURE ARRIVING FROM THE PACIFIC DURING NEXT EARLY WORK 
WEEK. ITS STILL TOO EARLY TO SAY WHICH SOLUTION MAY BE 
CLOSER...THOUGH AT THIS POINT IT CERTAINLY LOOKS LIKE A GOOD CHANCE 
OF PRECIPITATION WHICH HAS BEEN LACKING DURING THE MONTH OF 
NOVEMBER. SHOULD CONFIDENCE OF A WINTER STORM OR PRECIPITATION EVENT 
INCREASE...MENTION WILL BE NEEDED IN THE HAZARDOUS WEATHER OUTLOOK.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE AT THE KSLC 
TERMINAL THROUGH THE TAF PERIOD. SOUTHEAST DRAINAGE WINDS ARE 
EXPECTED TO SWITCH TO THE NORTHEAST LAKE BREEZE BETWEEN 18Z AND 20Z. 

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.

&&

$$

PUBLIC...ROGOWSKI
AVIATION...YOUNG

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)