Crashing the Timeline A Journal of Weather Interpretations and Possible Emergency Response Requirements January 28 – XX, 2016

NWS Forecast Maps – Baseline Assessment National Forecast Map, 1/28/16 Provided by WPC for expected wx for up to the next three days Summarizes large scale and significant weather forecasts from SPC, NHC, and WPC—severe wx, tropics, winter wx, flash floods Intended for public and EM uses Issued daily at 1000 UTC/0500 EST and updated at 1700 EST

Short Range Forecast Maps 24-hours out, issued 1/28/16 48-hour assessment also useful

Short Range Forecast Maps 48-hour forecast, 1/28/16 Note the approaching west coast storm—classic storm track for northwest and southwest rainfall followed by closed low pressure in four corners region, then ejection over continental divide with frontal system proceeding over plains

Medium Range Forecast Maps Days 3 & 4, 1/28/16: four corners low forming

Medium Range Forecast Maps Days 5 & 6, 1/28/16: low ejects to plains, severe wx scenario

WPC Forecast Surface Low Positions Day 1-3 surface low tracks reflect the ejecting low in Colorado

GFS 500MB Spaghetti Plot—Storm Tracks Uncertainty exists in all forecasts The further south the low ejects, the more likely that we could see severe wx on plains and Midwest Current/Days 1-2 Expected/Days 3-5

GFS Ensemble 500MB Plots—Day 3

GFS Ensemble 500MB Plots—Day 4

GFS Ensemble 500MB Plots—Day 5

GFS Ensemble 500MB Plots—Day 6

GFS Ensemble 500MB Plots—Day 7

WPC QPFs Days 1, 2, 3, 1/28/16: northwest rain to snow on the divide

WPC QPFs Days 4-5, 6-7, 1/28/16: ejected low, severe wx scenario

SPC Convective Outlooks Day 5 and Day 6 forecasts reflect the increasing risk of severe wx following low ejecting from divide region

Summary Interpretation: 1/28/16 Closed low with associated front drops down west coast, bringing rain to the northwest and southwest states Low progresses to the four corners region, spins up and strengthens, and then ejects across Rocky Mountains, bringing significant snow to high country—and IS a severe wx risk noted by increasing upslope flows in front range locations Low ejects onto Great Plains from Colorado, dips southward, and then progresses northeastward across the heartland, bringing increased likelihood of flash floods (low risk currently), convective threats (hail, tornadoes) along frontal boundary Low and front progress to the Great Lakes region, not likely to become a nor’easter risk, and then progresses off North American shores toward Greenland

Next Round of Weather: 1/28/16 Strong low affects Alaska at Day 3, stays offshore through Day 7 Not the same scenario as this week—not a west coast track that produces severe wx on plains

Recommended Actions GIS/Modeling/Analytics preparedness and connection with Watch based on MOTF 209-based GeoSitRep for planning support: Regions 9-10: Rainfall/landslide considerations (i.e., burn scars) Regions 7-8: Snowfall/ice considerations (plows/closures) Regions 3, 4, 5, 6, 7: Severe weather considerations (tornadoes, hail, rain) Regions 1-2: Nor’easter considerations (most likely not with this system) Hurricane Program/HLT only on east coast—need meteorologists for all CONUS regions/tie in physical scientists to MOTF/GISRCs Work with SPC on severe wx predictive analytics/exposure/losses Improve flash flood hazard/inundation mapping/loss atlas suites

Climatology Notes