Last Update: 7/29/10
@4:18pm
|
||
|
||
| Heat Idx: | 106.9°F | |
| Humidity: | 17% | |
| Dew Pt: | 54.0°F | |
| Wind: | South South West @ 2mph | |
| Gusts: | 7mph | |
| Pressure: | 29.81in/hg | |
| Trend: | Steady | |
| Rain Tdy: | 0.00in | |
| Rain Mth: | 0.02in | |
| Rain Yr: | 3.86in | |
Tonight![]() Partly Cloudy | Friday![]() Hot |
| Lo 79 °F | Hi 108 °F |
000 FXUS65 KVEF 292132 AFDVEF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 230 PM PDT THU JUL 29 2010 .SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED MAINLY ACROSS NORTHWEST ARIZONA AND SOUTHEAST NEVADA THROUGH FRIDAY WHILE A STABLE AIR MASS HOLDS OVER THE WESTERN HALF OF THE REGION. MONSOONAL MOISTURE MAY SPREAD WEST OF THE ARIZONA BORDER SATURDAY AND SUNDAY IN RESPONSE TO A LOW PRESSURE SYSTEM MOVING FROM ARIZONA TOWARD SOUTHERN CALIFORNIA. && .SHORT TERM...MOIST AND UNSTABLE AIR IS IN PLACE OVER MOHAVE COUNTY THIS AFTERNOON AND EXTENDS UP ACROSS EASTERN LINCOLN COUNTY AS WELL. THUNDERSTORMS WERE PRODUCING SOME HEAVY RAIN IN THE SOUTHERN PART OF MOHAVE COUNTY AND THESE STORMS FIRED UP ALONG THE BOUNDARY BETWEEN THE DRY AND MOIST AIR WHICH IS EVIDENT ON WATER VAPOR IMAGERY. THE MODELS ARE SHOWING LITTLE CHANGE THROUGH FRIDAY AND I CONTINUED TO FORECAST ISOLATED TO SCATTERED THUNDERSTORMS ACROSS MOHAVE COUNTY AND EASTERN LINCOLN COUNTY. THE GFS AND NAM12 DIFFER IN THAT THE GFS CONTINUES TO SHOW THE DRIER AND MORE STABLE AIR FARTHER EAST. THE FORECAST THROUGH FRIDAY IS MORE OR LESS A COMPROMISE BETWEEN THE TWO MODELS. MEANWHILE...A WAVE OVER SOUTHWEST NEW MEXICO THIS AFTERNOON WILL CONTINUE TO WEAKEN AND MOVE WESTWARD OVER THE NEXT FEW DAYS. THERE IS POTENTIAL FOR THIS FEATURE TO CAUSE MOISTURE TO INCREASE NORTHWESTWARD INTO MORE OF OUR FORECAST AREA SATURDAY THROUGH SUNDAY. MODELS WERE DIFFERING WITH THIS TREND WITH THE GFS ACTUALLY PUSHING THE MOISTURE AND INSTABILITY EASTWARD. EVEN THE NAM12 DOES NOT BRING THE MOISTURE AND INSTABILITY MUCH FARTHER WESTWARD THAN MOHAVE COUNTY. THIS GOES AGAINST MY INTUITION WITH THAT WAVE APPROACHING SO I PUT THUNDERSTORM CHANCES WEST INTO MUCH OF LINCOLN AND CLARK COUNTIES AND EASTERN SAN BERNARDINO COUNTY WITH THE HIGHEST POPS STILL IN MOHAVE COUNTY. I WAS EVEN CONCERNED THAT IF THAT WAVE HOLDS TOGETHER IT COULD CAUSE FAIRLY WIDESPREAD ORGANIZED CONVECTION AND A FLASH FLOOD WATCH MAY BE NEEDED FOR SATURDAY OR SUNDAY OR BOTH. WILL WAIT FOR LATER MODEL RUNS BEFORE MAKING THAT CALL HOWEVER. THE REST OF THE FORECAST AREA DEFINITELY LOOKS DRY AND STABLE. .LONG TERM...MONDAY THROUGH THURSDAY...THE INCREASED PRECIPITATION COVERAGE FROM THE WEEKEND UPPER LEVEL CIRCULATION WILL STILL BE AROUND MONDAY. IT DEPENDS ON THE MODEL AS TO HOW WIDESPREAD IT WILL BE...BUT MOST AGREE ON THE AREA THAT WILL BE IMPACTED THE GREATEST WILL BE MOHAVE COUNTY. AFTER MONDAY MODELS SHOW MINOR BITS OF ENERGY IN THE SOUTHWEST FLOW ON THE BACKSIDE OF THE SOUTHERN U.S. RIDGE. THIS SHOULD KEEP SOME ACTIVITY IN MOHAVE COUNTY FOR ANOTHER DAY OR TWO. ESSENTIALLY MADE BUT MINOR CHANGES TO THE PREVIOUS FORECAST...WHICH CALLS FOR DECREASED POP COVERAGE IN OUR EASTERN CWA EACH DAY AND FOR TEMPERATURES TO INCREASE A LITTLE TO NEAR NORMAL LEVELS BY WEDNESDAY. && .AVIATION...FOR MCCARRAN...WINDS WILL BE VARIABLE FROM 150-220 DEGREES AT ABOUT 10-12 KNOTS GUSTING TO NEAR 20 KNOTS THROUGH ABOUT 02-03Z. CLOUDS WILL VARY FROM SCATTER TO BROKEN AT ABOUT 15K FT THIS AFTERNOON AND EVENING AND SHOULD GO BROKEN THIS EVENING AND STAY THAT WAY. IT IS POSSIBLE FOR THUNDERSTORMS TO FORM OVER THE SPRING AND SHEEP MOUNTAINS THIS AFTERNOON AND EVENING AND AGAIN FRIDAY AFTERNOON. NOT EXPECTING ANY THUNDERSTORMS IN THE VALLEY BUT OUTFLOWS FROM DISTANT STORMS IN ARIZONA COULD INFLUENCE THE WINDS AT KLAS TONIGHT. THE PEACH SPRINGS CORRIDOR WILL SEE ISOLATED THUNDERSTORMS THIS AFTERNOON/EVENING AND FRIDAY AFTERNOON. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...WINDS WILL GENERALLY FOLLOW A DIURNAL PATTERN AND REMAIN AROUND 10-15KTS. FOR THURSDAY AND FRIDAY AFTERNOONS AND EVENINGS ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE IN MOHAVE COUNTY ARIZONA AND IN LINCOLN COUNTY NEVADA. THE ARIZONA STORMS WILL HAVE HEAVY RAINFALL RATES ACCOMPANY THEM. OUTFLOW BOUNDARIES FROM THE STORMS WILL MAKE FOR ERRATIC AND GUSTY CONDITIONS NEAR THEM. & .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && $$ HARRISON/JACQUES HTTP://WEATHER.GOV/LASVEGAS |