IN THE NORTHEAST PACIFIC DURING 2014-2016 ONE OF THE LARGEST RECORDED MARINE HEAT WAVES (MHWS) OCCURRED KNOWN IN THE POPULAR PRESS AS "THE BLOB". THE MHW CAUSED MAJOR DAMAGE TO ECONOMICALLY IMPORTANT FISHERIES AND OTHER ECOSYSTEMS FROM ALASKA THROUGH CALIFORNIA ASSOCIATED WITH SPECIES SHIFTS AND AN UNPRECEDENTEDLY LARGE BLOOM OF TOXIC ALGAE THAT SPANNED THE ENTIRE COASTLINE. THOUGH THE BLOB AFFECTED THE ENTIRE NORTHEAST PACIFIC THE SEA-SURFACE TEMPERATURE (SST) ANOMALIES ALONG THE WEST COAST OF THE UNITED STATES IN SUMMER WERE MUCH STRONGER ALONG THE SOUTHERN HALF OF THE COASTLINE CALIFORNIA AND BAJA THAN THE NORTHERN HALF WASHINGTON AND OREGON. THIS NORTH-SOUTH DIFFERENCE WAS SO STRONG BY SUMMER 2015 THAT THE BLOB SPLIT IN TWO PARTS ONE IN THE GULF OF ALASKA AND ONE EXTENDING FROM CENTRAL CALIFORNIA TO BAJA; THE SPLIT WAS REPORTED IN THE JOURNAL SCIENCE AS "FLUMMOXING" SCIENTISTS. THE REASON FOR THE SPLITTING OF THE MHW HAS REMAINED UNCLEAR BUT THE STRONG REGIONAL VARIATION IN SST ANOMALIES IS CONSISTENT WITH REGION-SPECIFIC VARIATIONS IN FREQUENCY OF MHWS WORLDWIDE. THE SCIENTIFIC COMMUNITY'S LACK OF UNDERSTANDING OF THE CAUSES OF REGIONAL VARIATION WITHIN MHWS PREVENTS ACCURATE PREDICTION OF MHWS AND THE ECONOMIC AND ECOLOGICAL IMPACTS. WE OBSERVE A STRIKING SIMILARITY BETWEEN THE SST PATTERN OF THE SPLIT BLOB AND A CHARACTERISTIC QUASI-DIPOLE WIND PATTERN WE RECENTLY DESCRIBED OFF WESTERN NORTH AMERICA. UNTIL NOW HOWEVER THIS QUASI-DIPOLE WIND PATTERN HAS NOT BEEN CONSIDERED AS A POSSIBLE CAUSE OF REGIONAL VARIATION IN SST ANOMALIES DURING MHWS OFF WESTERN NORTH AMERICA. WE OBSERVE AN ANALOGOUS PATTERN IN SST AND WIND STRESS OFF WESTERN SOUTH AMERICA DURING THE MHW IN JANUARY 2016 SUGGESTING THE SPLIT MHW PATTERN IS A PHENOMENON EXHIBITED BY MULTIPLE EASTERN OCEAN BASINS. OBJECTIVES WE PROPOSE TO DETERMINE WHETHER THERE IS A SYSTEMATIC RELATIONSHIP BETWEEN THE CHARACTERISTIC REGIONAL WIND FORCING PATTERNS ALONG EASTERN OCEAN BOUNDARIES IN SUMMER AND THE SPATIAL STRUCTURE INTENSITY AND PERSISTENCE OF MIDLATITUDE MHWS. WE HYPOTHESIZE THAT: 1. DURING MHWS THE REGIONAL WIND DIPOLE MODE PERSISTS IN ONE STATE REDUCING AND INCREASING SST IN THE POLEWARD AND EQUATORWARD PARTS OF THE DOMAIN RESPECTIVELY AND "SPLITTING" THE MHW; 2. DURING MORE TYPICAL SYNOPTIC RIDGING EVENTS THE WIND DIPOLE ITSELF CAN CREATE A SHORTER-LIVED MHW IN THE TYPICAL RELAXATION REGION. IF THERE IS A DIRECT RELATION BETWEEN THE SST PATTERN DURING MIDLATITUDE MHWS AND THE CHARACTERISTIC DIPOLE WIND PATTERN WE WILL BE ABLE TO DETERMINE WHICH AREAS ALONG WESTERN NORTH AND SOUTH AMERICA ARE LIKELY TO HAVE STRONG OR WEAK SST ANOMALIES DURING FUTURE MHWS. THIS WORK WILL INFORM FUTURE STUDIES ALONG MIDLATITUDE EASTERN OCEAN BOUNDARIES IN THE ATLANTIC. METHODS WE WILL USE OUR RECENTLY DEVELOPED APPLICATION OF HILBERT EMPIRICAL ORTHOGONAL FUNCTION (HEOF) ANALYSIS [FEWINGS 2017] TO ANALYZE SATELLITE SCATTEROMETER L2 SWATH OCEAN VECTOR WINDS SST AIR-SEA HEAT FLUXES INCLUDING OAFLUX AND REANALYSIS PRESSURE FIELDS. WE WILL ANALYZE ALL SUMMER MHWS IN BOTH EASTERN SUBTROPICAL PACIFIC BASINS DURING THE SCATTEROMETER RECORD 2000-2017 WHICH INCLUDES AT LEAST ~15 MHWS OFF NORTH AMERICA. THIS WILL BE ONE OF THE FEW STUDIES OF THE RECENT MHWS TO RESOLVE THE UNDERLYING SYNOPTIC-SCALE PROCESSES THAT CONTRIBUTE MOST OF THE VARIANCE IN WINDS AND SST RATHER THAN USING MONTHLY AVERAGES. RELEVANCE TO NASA THIS PROJECT IS RELEVANT TO THE OVWST 2017 SOLICITATION BECAUSE OUR PRIMARY DATA SETS ARE LEVEL 2 SATELLITE OCEAN VECTOR WINDS. THIS WORK REQUIRES L2 OCEAN VECTOR WIND SWATH DATA IN ORDER TO CALCULATE WIND STRESS CURL AND TO ANALYZE WIND STRESS AND WIND VELOCITY ALONG THE COAST WHERE REANALYSIS WIND FIELDS ARE INACCURATE. WE WILL USE RAPIDSCAT DATA AND OUR PROJECT IS SYNERGISTIC WITH THE NASA SST SCIENCE TEAM: WE WILL USE GHRSST L2P AND L4 MUR NASA SATELLITE SST DATA. THIS PROJECT ALSO USES THE OVWST OAFLUX AIR-SEA FLUX PRODUCTS.