Heavy Rain and Thunderstorms in the Lower Ohio Valley and Southeast; Flooding Continues Along the East Coast of Florida

An approaching cold front may produce isolated heavy rainfall and severe weather today over portions of the Lower Ohio Valley and Southeast. While the heavy rainfall is ending across east Florida, significant river flooding is forecast along the St. John’s and the Peace rivers through the end of the week as flood waters will be slow to recede. Read More >

Multi-Radar Multi-Sensor (MRMS) v12.3.0

ProbSevere version 3

Every two minutes, the ProbSevere (PS) model outputs a geoJSON containing a collection of features, each of which contains a polygon, the ProbSevere, ProbTor, ProbHail, and ProbWind probabilities, and associated environmental information (“properties”). In MRMS v12.3, PS is being upgraded from Version 2 (PSv2) to Version 3 (PSv3). PSv3 features contain different environmental information than PSv2 features did.
PSv2 geoJSONs are available from https://mrms.ncep.noaa.gov/ProbSevere/PROBSEVERE.
During testing, PSv3 geoJSONs will be available from https://mrms-qa.ncep.noaa.gov/ProbSevere/PROBSEVERE.

{feature number} -> models -> probsevere

The following table compares the names of each of the environmental parameters listed in the ‘probsevere’ portion of each PS feature across versions 2 and 3:

Key	PSv2 value	PSv3 value
PROB	{ProbSevere probability}	{ProbSevere probability}
LINE01	ProbHail; ProbWind; ProbTor	ProbSevere; ProbHail; ProbWind; ProbTor
LINE02	MESH	MESH; VIL
LINE03	VIL Density	ENI Flash Rate
LINE04	Flash Rate	ENI Flash Density
LINE05	Flash Density (max in last 30 min)	Max LLAzShear
LINE06	Max LLAzShear	98% LLAzShear
LINE07	98% LLAzShear	98% MLAzShear
LINE08	98% MLAzShear	Norm. vert. growth rate
LINE09	Norm. vert. growth rate	EBShear; SRH 0-1km
LINE10	EBShear; SRH 0-1km AGL	MeanWind 1-3km
LINE11	MUCAPE; MLCAPE; MLCIN	LR 0-3km; Max LR 2-6km
LINE12	MeanWind 1-3kmAGL	MUCAPE; MLCAPE; MLCIN
LINE13	Wetbulb 0C hgt	Wetbulb 0C hgt; PWAT
LINE14	CAPE -10C to -30C; PWAT	GLM: max FED; sum FCD
LINE15	Avg. beam height (ARL)	GLM: max TOE; min flash area

Table 1. Comparison of ‘probsevere’ components of PS features between versions 2 and 3.

{feature number} -> models -> probtor

There are no changes to the ‘probtor’ section of ProbSevere features in this release.

{feature number} -> models -> probhail

There are no changes to the ‘probhail’ section of ProbSevere features in this release.

{feature number} -> models -> probwind

The following table compares the names of each of the environmental parameters listed in the ‘probwind’ portion of each PS feature across versions 2 and 3:

Key	PSv2 value	PSv3 value
PROB	{ProbWind probability}	{ProbWind probability}
LINE01	ProbWind	ProbWind
LINE02	MESH	MESH
LINE03	VIL Density	Flash Rate
LINE04	Flash Rate	98% LLAzShear
LINE05	98% LLAzShear	98% MLAzShear
LINE06	98% MLAzShear	Norm. vert. growth rate
LINE07	Norm. vert. growth rate	EBShear
LINE08	EBShear	MeanWind 1-3kmAGL
LINE09	MeanWind 1-3kmAGL	MUCAPE; MLCAPE
LINE10	MUCAPE; MLCAPE	[no LINE10 in PSv3]

Table 2. Comparison of ‘probwind’ components of PS features between versions 2 and 3.

{feature number} -> properties

The “VIL_DENSITY”, “MAXRC_ICECF”, and “PS” attributes from ProbSevere v2 are removed in v3 and the format of “AVG_BEAM_HGT” is modified. Several new attributes are included in the “properties” section of each ProbSevere v3 object. Removed attributes are indicated with strikethrough and new attributes are highlighted in green in the below example object:

"properties": {

"MaxFED": "8",

"MaxFCD": "2",

"AccumFCD": "10",

"MaxTE": "28",

"MinFlashArea": "80",

"TE@MaxFCD": "12",

"AvgGroupArea": "277",

"MUCAPE": "948",

"MLCAPE": "428",

"MLCIN": "-6",

"EBSHEAR": "22",

"SRH01KM": "52",

"MEANWIND_1-3kmAGL": "14",

"COMPREF": "62.0",

"REF20": "60",

"REF10": "62",

"MESH": "1.29",

"VIL_DENSITY": "1.54",

"H50_Above_0C": "6.2",

"EchoTop_50": "4.0",

"VIL": "34",

"FLASH_RATE": "13",

"FLASH_DENSITY": "0.25",

"MAXLLAZ": "0.008",

"P98LLAZ": "0.007",

"P98MLAZ": "0.006",

"MAXRC_EMISS": "0",

"MAXRC_ICECF": "N/A",

"ICP": "70",

"WETBULB_0C_HGT": "6.2",

"PWAT": "0.8",

"CAPE_M10M30": "323",

"LLLR": "8.9",

"MLLR": "7.6",

"DCAPE": "472",

"SRW02KM": "17.4",

"SRW46KM": "23.6",

"LCL": "1149",

"LJA": "0.1",

"MLAT": "46.65",

"MLON": "-110",

"SIZE": "221",

"AVG_BEAM_HGT": "1.17 kft / 0.36 km",

"AVG_BEAM_HGT": "8.4",

"MOTION_EAST": "9.1",

"MOTION_SOUTH": "0",

"ProbSevere": "30",

"ProbHail": "30",

"ProbWind": "3",

"ProbTor": "3",

"PS": "9",

"ID": "27"

}

Heavy Rain and Thunderstorms in the Lower Ohio Valley and Southeast; Flooding Continues Along the East Coast of Florida

MRMS v12.3 Supplemental