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ZCZC NFDSPENES ALL SPENES HIZ000- . SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 05/04/19 1613Z SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-683-1404 LATEST DATA USED: GOES-17 SWIR 1510Z, BLENDED TPW 1336Z, GPS PWS 1400Z, MIMIC-TPW2 1400Z; AMSU-RAIN 1530Z KH . LOCATION...HAWAII... . ATTN WFOS...HFO... ATTN RFCS...APRFC... . EVENT...UNSEASONAL COLD FRONT AND MIDDLE/UPPER ATMOSPHERIC CLOSED LOW . SATELLITE ANALYSIS AND TRENDS...LATEST GOES-17 WATER VAPOR IMAGERY DEPICTS A SLOW MOVING, SIZABLE, WELL DEFINED MIDDLE/UPPER ATMOSPHERIC LOW N-NNW OF THE MAIN HAWAIIAN ISLAND CHAIN. THIS FEATURE, ALONG WITH A SUBTROPICAL JET JUST TO THE SOUTH OF THE BIG ISLAND, IS PROVIDING DIFFLUENT FLOW ALOFT THAT IS AIDING IN UVV ACROSS HAWAII. MICROWAVE IMAGERY AND SURFACE OBSERVATIONS AGREE IN SHOWING A POOLING OF MOISTURE NEAR AND ALONG A SURFACE COLD FRONT MOVING ESE THROUGH THE ISLANDS. THIS DATA ALSO SHOWS A NORTHWARD TRANSPORT OF DEEPER TPW ENCROACHING UPON THE BIG ISLAND. AS OF 1500Z, THE FRONT COULD BE OBSERVED IN SWIR IMAGERY JUST TO THE EAST OF KAUAI. SURFACE OBSERVATIONS CONFIRM THIS, AS A WIND SHIFT WAS OBSERVED BETWEEN 14Z AND 15 Z ACROSS KAUAI. A COUPLE HUNDRED MILES NORTH OF THE ISLANDS, MICROWAVE DATA WAS SUGGESTING RAIN RATES BETWEEN 0.75 INCHES AND 1 INCH PER HOUR. CLOUD TOP TEMPERATURES REMAIN WARM NEAR THE FRONT, SUGGESTING THAT RAIN PROCESSES COULD POSSIBLY BE QUITE EFFICIENT WITH THE ONGOING ACTIVITY. . AN ANNOTATED SATELLITE GRAPHIC SHOWING THE HEAVY PRECIPITATION THREAT AREA SHOULD BE AVAILABLE ON THE INTERNET ADDRESS LISTED BELOW IN APPROXIMATELY 10-15 MINUTES. . SHORT TERM OUTLOOK VALID 1615-2215Z...MEDIUM CONFIDENCE FACTOR IN SHORT TERM OUTLOOK...AS THE COLD FRONT PUSHES ESE OVER THE NEXT FEW HOURS, THE POOL OF MOISTURE WILL MOVE ALONG WITH THE FRONT. THE FRONT WILL BE MOVING INTO A REGION WHERE FLOW ALOFT IS SLIGHTLY MORE DIFFLUENT AND COULD SPUR DEEPER DEVELOPMENT AS THE FRONT MOVES ACROSS OAHU, MAUI, MOLOKAI, LANAI, KAHOOLAWE, AND THE BIG ISLAND. LIMITING THIS THREAT WOULD BE AN OBSERVED DECREASE IN INSTABILITY PER THE 12Z PHLI AND PHTO RAOBS. AS THE SUN BEGINS TO RISE, INSTABILITY COULD REBOUND AS SKIES FROM OAHU TO THE BIG ISLAND ARE RELATIVELY CLEAR AND SURFACE TEMPERATURES WILL RISE. ANOTHER LIMITING FACTOR WITH THIS THREAT WOULD BE THE RELATIVELY PROGRESSIVE NATURE OF THE FRONT, AS FORWARD MOVEMENT IS ABOUT 15-20 MILES PER HOUR. THIS WOULD, TO AN EXTENT, LIMIT THE AMOUNT OF TIME ANY ONE POINT WOULD OBSERVE THE HEAVIEST RAINFALL. . ....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 2271 15961 1993 15390 1864 15565 2157 16074 . NNNN |
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