|
ZCZC NFDSPENES ALL SPENES HIZ000- . SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 03/31/18 1731Z SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-683-1404 LATEST DATA USED: GOES-WEST:1700Z JS . LOCATION...HAWAII... . ATTN WFOS...HFO... ATTN RFCS...APRFC... . EVENT...AREA OF MODERATE TO HEAVY RAIN AND EMBEDDED CONVECTION APPROACHING THE WESTERN HAWAIIAN ISLANDS. . SATELLITE ANALYSIS AND TRENDS...THE LARGER PICTURE FROM WATER VAPOR ANIMATION REVEALS THE WESTERN HAWAIIAN ISLANDS ARE ON THE SOUTHERN END OF A VERY LONG NORTH-SOUTH ELONGATED BAROCLINIC ZONE WITH PRIMARY LARGE MID/UPPER CIRCULATION CENTER LOCATED WELL UP TO THE NW AROUND 40N165W. ANIMATION OF THE PAST COUPLE OF DAYS SHOWS THE SOUTHERN EXTENT OF A MID/UPPER LEVEL TROF AXIS, DEPICTED BY MID LEVEL DRY AIR/DARK SWATH ON WATER VAPOR IMAGERY, HAS PROGRESSED STEADILY EASTWARD APPROACHING THE WESTERN ISLANDS WITH CURRENT POSITION ROUGHLY ALONG 165W TO THE WEST OF HAWAII. SOME BETTER IR SATELLITE ENHANCEMENT HAS OCCURRED WITHIN THE BAROCLINIC ZONE WEST OF HAWAII OVER THE PAST 12 HOURS DUE IN PART TO THE APPROACH OF A MID/UPPER LEVEL DISTURBANCE NOW NEAR 23N160W (BECOMING OBSCURED BY HIGHER CLOUDS) AND AN INCREASE IN UPPER LEVEL WINDS ALONG THE W END OF THE BAROCLINIC BAND TO THE NW OF HAWAII WHICH PLACES THE WESTERN ISLANDS IN CLOSER PROXIMITY TO THE MORE FAVORABLE RIGHT ENTRANCE REGION. IN ADDITION, CONFLUENT LOWER LEVEL FLOW HAS HELPED DRAW DEEPER MOISTURE TO THE NE FROM THE TROPICS WITH RECENT AMSU PASS INDICATING PW VALUES OF UP TO 1.75" NEARING THE WESTERN ISLANDS WHICH WOULD BE A FURTHER INCREASE FROM THE NEAR 1.5" PW VALUE IN THE 12Z PHLI SOUNDING. THIS RECENT AMSU PASS FROM AFTER 14Z ALSO IS NOW PICKING UP ON SOME OF THE HEAVIER RAIN CORES WEST OF HAWAII WITH AREAL AVERAGE RAIN RATES OF UP TO .50"-.75"/HR WHICH ALONG WITH THE PRESENCE OF A FEW LIGHTNING STRIKES CERTAINLY IMPLIES LOCALLY HIGHER RAIN RATES WITH THE STRONGER CONVECTIVE ELEMENTS. THE APPEARANCE OF NARROW CAPE UP TO NEAR 250MB FROM THE PHLI 12Z SOUNDING ALSO IS INDICATIVE OF AN ENVIRONMENT SUPPORTING THE POTENTIAL FOR CONVECTIVE ACTIVITY. . SHORT TERM OUTLOOK VALID 1730-2330Z...MEDIUM TO HIGH CONFIDENCE FACTOR IN SHORT TERM OUTLOOK...THROUGH THE OUTLOOK PERIOD, EXPECT THE SHIELD OF MODERATE TO HEAVY RAIN WITH SOME EMBEDDED CONVECTION TO CONTINUE TO SPREAD ACROSS KAUAI AND TOWARD OAHU WITH THE LIKELIHOOD FOR RAIN RATES TO EXCEED THE AREAL AVERAGE AMSU RATES NOTED ABOVE OVER KAUAI AND ESPECIALLY IN THE TERRAIN ORIENTED FAVORABLY WITH THIS PARTICULAR LOWER LEVEL FLOW. THE STEADY EASTWARD MOVEMENT OF THE ENHANCED IR SIGNATURE SHOULD SERVE AS A MITIGATING FACTOR SO THE MAJORITY OF THE HEAVY RAIN THREAT WOULD TEND TO COME MORE FROM HIGHER RATES THAN DURATION. HOWEVER, EVEN AS THE MORE ENHANCED SHIELD MOVES EAST OF THE WESTERN ISLANDS SATELLITE IMAGERY SUGGESTS THE LOWER LEVEL BOUNDARY WILL BE SLOWER TO PROGRESS LEAVING THE THREAT FOR LOWER TOPPED SHOWER ACTIVITY BEYOND THIS PERIOD. . ....NESDIS IS A MEMBER OF NWSCHAT (NESDISSATELLITEPRECIP).... ....NESDIS IS A MEMBER OF 12 PLANET.... . FOR QUESTIONS AND COMMENTS CONCERNING THE SATELLITE PRECIPITATION MESSAGES AND GRAPHICS PLEASE EMAIL SSDPrecip@noaa.gov . FOR PRECIP MESSAGES AND GRAPHICS ON THE WEB: http://www.ospo.noaa.gov/Products/atmosphere/spe/ . FOR AUTOMATED SATELLITE PRECIPITATION ESTIMATES ON THE WEB: http://www.star.nesdis.noaa.gov/smcd/emb/ff/CONUS.php . LAT...LON 2260 15761 2101 15772 2100 16038 2259 16049 . NNNN |
No Graphics Available
|