Peter Mullinax
@wxmvpete
Meteorologist at NOAA's Weather Predicition Center. Proud father & husband. Northern VA raised, DC sports fan. My thoughts & opinions are my own.
Updated Day 1 High Risk had a small expansion a little farther N&W, but not too much change. More rounds of storms expected overnight tonight and into Friday AM.
The overnight WPC crew upgraded today's Day 1 ERO to a High Risk amid the ongoing catastrophic flooding. Per the Day 1 discussion, "Areas of slow-moving, heavy rainfall are expected to continue beyond 12Z, exacerbating the catastrophic impacts that unfolded across portions of the region overnight."
Two High Risks were issued in central TX on dayshift. One for the remainder of today and the other for Wednesday. Overnight flooding is likely. Be sure to have multiple ways of receiving weather alerts!
I will be on the dayshift Excessive Rainfall Outlook at WPC the next few days. TX is the focus, but no shortage of flash flood potential from the Sothwest to the Southeast today. Even some pockets of Marginals in MT & New England.
A High Risk was issued this morning for the Central Gulf Coast. High Risks are not issued lightly & indicate the potential for both widespread & life-threatening flash flooding.
SPC upgraded to a Moderate Risk in northern IL & northern IN, while this moisture-loaded system also poses a flash flood threat, highlighted in WPC's Slight Risk. It is bound to be an active & potentially dangerous day in the Midwest. Have a reliable means for receiving warnings!
A dynamic setup on Wednesday with low pressure that is among the lowest observed in the 1979-2021 ERA5 database will overlap with a remarkably strong jet stream aloft, robust low-level jet, & powerful IVT to produce a combination of severe & hydro impacts in the Midwest.
WPC has initiates Key Messages for the impending heat wave over the eastern half of the U.S..
Today's heavy snow discussion marks the end of WPC's winter weather desk being staffed for the 2025-26 cold season. Just in time for the conclusion of the Central Rockies winter storm! What a season it was in the East. The desk will resume being fully staffed in late September.
Rare late day update to the Key Messages as new guidance continues to trickle in. Confidence is increasing in a highly impactful winter storm Sunday into Monday along the Northeast coast with disruptive snowfall as far inland as the western suburbs of I-95.
WPC has initiated Key Messages for this impending Nor'easter. While confidence in a storm system have increased, exact details on amounts & resulting impacts remain highly subjected to storm track. Continue to follow WPC's and your local WFO's forecast for the latest.
I expect some measurable snow in the Mid-Atlantic with areas east of I-95 favored for the heaviest snowfall, as well as N&W of the 500mb low (eastern PA). Think the WSSI-P Minor probabilities (24hr probs 12Z Sun - 12Z Mon, noting that for southern New Englanders) show that well.
The past 5 EC-AIFS ensemble runs have been coming in stronger, but lingering spread in how these vorticity maxima behave remains. There are still quite a few members with snow only via the inverted trough, & some with little at all. It speaks to the lingering volatility.
Speaking for the DC/Baltimore area- I would rather have that closed 500mb contour either closer to the NC/VA border, or in the GFS case if it is not fully closed, to be negatively titled. In this case, it is still working towards both by 00Z Mon when the storm is already offshore
Spread in the past 5 EC-AIFS ENS runs has steadily decreased. But where there is lingering spread, it largely comes down to phasing & 500mb trough position & tilt. There is also lingering spread south of Nova Scotia, hinting at ongoing differences in wave separation & confluence.
An exceptional winter storm that has the Carolinas, eastern TN, and northeast GA in its sights will produce a swath of heavy snow, including potential blizzard conditions along the NC coast this weekend.
A major winter storm is set to produce heavy snow, whiteout conditions, and potentially blizzard conditions in parts of the southern Mid-Atlantic this weekend. Impacts stretch as far south as Atlanta & even Savannah. You can read the WPC discussion here: www.wpc.ncep.noaa.gov/discussions/...
The latest Key Messages continue to identify the Carolinas & Southesst VA as facing the worst impacts. Unlike the last winter storm, high winds & blowing snow are a bigger concern, especially along the coasts.
Good morning! Key Messages have begun for the eastern U.S. winter storm.
I left last week to the start of one winter storm, to coming back from my weekend off to another. I try to dive into some of the scenarios & why this weekend forecast is far from a lock: www.wpc.ncep.noaa.gov/discussions/...
This is why there remains such exceptional spread in position & intensity of the storm location. Over the last 24 hours, the only thing that increased in confidence is there is likely to be a strong coastal low. Beaches are likely to take a pounding. Otherwise, a lot of ?s remain
Regarding the East Coast winter storm threat-- 06Z EC-AIFS ensembles still show high spread in a few areas: 1. The shortwave trough placement/amplitude/tilt as it track off the East Coast, 2. suppression feature south of Nova Scotia, 3. trailing shortwave in Central Plains.
Latest WPC post: "Here is the latest information regarding a potentially significant coastal storm this weekend. Chances have increased for impactful snow and/or wind along the immediate East Coast, but uncertainty remains rather high with respect to details. Be sure to keep checking for updates!"
12Z Dulles, VA sounding eqrlier this morning. Got family nearby that under 1 hour later were reporting sleet. The warm nose in the 700-750mb layer is the culprit.
Here are the latest Key Messages from WPC which now sport total snow and ice accumulations forecasts.
Here's the updated Key Messages from this afternoon, now highlighting the potential for locally catastrophic ice accumulations. The snow and ice is going nowhere any time soon in the east. In fact, some guidance shows much of the Northeast may struggle to get above freezing before the end of January
As Euro ensembles gradually come into better agreement on their swath of heaviest snow, the Euro EFI becomes very useful. It tells us how unusual & extreme a specific weather variable can be based on thousands of reforecasts over a 5-week period centered on that day.