baltimoresun.com

« Overnight rains tops 2" - 4" south of Baltimore | Main | Should schools be closing due to heavy rain? »

September 30, 2010

More rain coming; NWS says some could see 12"

UPDATE, 12:30 p.m.: The National Weather Service has extended the Flash Flood Watch until 6 a.m. Friday. "There is increasing concern that moderate to heavy rain will continue in the I-95 corridor until past midnight." 

Portions of Maryland between the Blue Ridge and the Chesapeake Bay could see a whole lot more rain than we've clocked so far. Check out this from the National Weather Service's morning forecast discussion:

"WIDESPREAD HEAVY RAIN WILL CONTINUE ACROSS THE ENTIRE [FORECAST AREA].
MESOSCALE BANDS OF HEAVY RAIN WILL ENHANCE RAINFALL RATES TO
Rain runoffAROUND 3-4 INCHES PER HOUR ALONG AND EAST OF THE I-95 CORRIDOR.

"AN ADDITIONAL 2-3 INCHES OF RAIN CAN BE EXPECTED EAST OF THE BLUE
RIDGE WITH LOCALLY HIGHER AMOUNTS OF 6 INCHES ACROSS THE WESTERN SHORE
OF THE CHSPK BAY. WE COULD BE TALKING ABOUT STORM-TOTAL RAINFALL
AMOUNTS LOCALLY OVER A FOOT
ALONG THE WESTERN SHORE."

Prof. Jeffrey Halverson, at UMBC, says he's worried we may see a second slug of heavy rain tonight as a second low, the actual remains of Tropical Storm Nicole, cruise past the region.

Eric the Red agrees:

"The second low, which is the actual remant circulation of Nicole, is expected to lift north toward the region tonight.  Models differ on the speed... with the GFS [model] bringing heavy, heavy rain from this system into the region this eve, and has it ending by tomorrow morning. 

"The NOGAPS has similar timing.  The Canadian and UKMET are slower... and have the torrential downpours with this second part of the event occurring a bit later tonight into tomorrow.  Since the second low - remnants of Nicole - are expected to pass just to our east, the tornado threat is not as great (thankfully).  I think a compromise in timing makes sense... so an additional period of heavy rain tonight and ending in the morning.

"Total rainfall amounts under this new scenario double, if not more.  4-8" will be widespread, with the Tides Onlinepotential for higher amounts.  If Nicole strays a bit to the east, then rainfall amounts will be less.  I guess I've seen enough to buy into the double-whammy."

UPDATE, 12:20 p.m.: BWI-Marshall has recorded 3.46 inches of rain so far from this storm, bringing the month's total to more than 5.5 inches. Normal precipitation for BWI in September is 3.98 inches.

Meanwhile, there is still a Coastal Flood Warning up for the Western Shore. The high tide at Baltimore (chart) appears to be running about 2 feet above predictions.

Posted by Frank Roylance at 10:44 AM | | Comments (9)
Categories: Forecasts
        

Comments

Seriously? Seriously?!

Working in DC, live in Annapolis and wondering how in the heck I'm going to make it home tonight.

Great ooggolly bugolly! Twelve inches of rain coming at us is mesoscale bands. This should be interesting.

It looks like the heaviest rain has eased eastward as the shot of rain comes north. The lower shore might get a decent amount after all, but it looks like areas west of I-95 might be done with the heavy stuff.

FR: Or maybe not, if this water vapor satellite loop is any guide. Could be more on the way. http://bit.ly/dk9jlq

Imagine if this was a snow storm!

I think Professor Halverson and Eric are right. Looking at the latest radar loops (3pm), you can see Nicole spinning into South and North Carolina. The storm that has passed through is to our North and East, and looks to keep heading in that general direction. But Nicole is currently taking an almost due-North path. If she holds to that, then the core of the storm will pass near enough to directly over Baltimore. That would be major ugly.

I guess it all ends up depending on how far East (and at what stage in her journey North) Nicole gets pulled by the front that is influencing everything in this area. We're either going to dodge a bullet, or tonight will be epic for the Washington-Baltimore corridor and counties west.

And if the remnants of Nicole actually shift even a little bit further West as it comes over our area, then the tornado risks increase, yes? That would mean the eastern side of the spin would be pulled over us, which is the more unstable, faster-moving air.

Am I understanding the dynamics correctly?

Its 7:30pm and the current satellite imagery shows the center of the Nicole low coming right smack over the Gaithersburg area if it stays on the current northerly heading, a large swath of heavy rain is just starting to touch points due south of Frederick County, if this precipitation stays on this northerly course, another 4+ inches is not out of the question. My rain guage in Middletown is at 5.5 inches since last night-wow. talk about a drought buster, 1/4 a years worth of rainfall in 30 hours, (assuming another 4 inches falls tonight)....

FR: Only 2.5 inches on the WeatherDeck in Cockeysville. But the rain seems to be picking up again.

Told you yesterday there were several models that said this would be a two part system, with a second round and more flooding tonight.

All the gurus first acted like this was a non-event and called for showers, then less tha 24hrs before the storm they upped it to 2-4", then 2-6", now it is up to 12" in some areas. The Canadian, UK and NOGAP were all over this scenario yesterday but the experts dissed it.

Take alook at the NWS total precip loop for Sterling and see hoe close 5-6" are from the"weatherdeck". Figuer the rain will let up by 3am. Western shore and Harford will see 5-12" by the time it ends.

Funny how after this week I don't hear any of the alarmists bellyaching about terrible drought conditions and its impending disaster to all of us....I wonder where they've all gone???

Post a comment

All comments must be approved by the blog author. Please do not resubmit comments if they do not immediately appear. You are not required to use your full name when posting, but you should use a real e-mail address. Comments may be republished in print, but we will not publish your e-mail address. Our full Terms of Service are available here.

Verification (needed to reduce spam):

About Frank Roylance
This site is the Maryland Weather archive. The current Maryland Weather blog can be found here.
Frank Roylance is a reporter for The Baltimore Sun. He came to Baltimore from New Bedford, Mass. in 1980 to join the old Evening Sun. He moved to the morning Sun when the papers merged in 1992, and has spent most of his time since covering science, including astronomy and the weather. One of The Baltimore Sun's first online Web logs, the Weather Blog debuted in October 2004. In June 2006 Frank also began writing comments on local weather and stargazing for The Baltimore Sun's print Weather Page. Frank also answers readers’ weather queries for the newspaper and the blog. Frank Roylance retired in October 2011. Maryland Weather is now being updated by members of The Baltimore Sun staff
-- ADVERTISEMENT --

Sign up for FREE weather alerts*
Get free Baltimore Sun mobile alerts
Sign up for weather text alerts
SKY NOTES WEATHER

Returning user? Update preferences.
Sign up for more Sun text alerts
*Standard message and data rates apply. Click here for Frequently Asked Questions.
Maryland Weather Center


Area Weather Stations
Resources and Sun coverage
• Weather news

• Readers' photos

• Data from the The Sun's weather station

• 2011 stargazers' calendar

• Become a backyard astronomer in five simple steps

• Baltimore Weather Archive
Daily airport weather data for Baltimore from 1948 to today

• National Weather Service:
Sterling Forecast Office

• Capital Weather Gang:
Washington Post weather blog

• CoCoRaHS:
Community Collaborative Rain, Hail and Snow Network. Local observations by volunteers

• Weather Bug:
Webcams across the state

• National Data Buoy Center:
Weather and ocean data from bay and ocean buoys

• U.S. Drought Monitor:
Weekly maps of drought conditions in the U.S.

• USGS Earthquake Hazards Program:
Real-time data on earthquakes

• Water data:
From the USGS, Maryland

• National Hurricane Center

• Air Now:
Government site for air quality information

• NWS Climate Prediction Center:
Long-term and seasonal forecasts

• U.S. Climate at a Glance:
NOAA interactive site for past climate data, national, state and city

• Clear Sky Clock:
Clear sky alerts for stargazers

• NASA TV:
Watch NASA TV

• Hubblesite:
Home page for Hubble Space Telescope

• Heavens Above:
Everything for the backyard stargazer, tailored to your location

• NASA Eclipse Home Page:
Centuries of eclipse predictions

• Cruise Critic: Hurricane Zone:
Check to see how hurricanes may affect your cruise schedule

• Warming World:
NASA explains the science of climate change with articles, videos, “data visualizations,” and space-based imagery.

• What on Earth:
NASA blog on current research at the space agency.
Most Recent Comments
Blog updates
Recent updates to baltimoresun.com news blogs
 Subscribe to this feed
Charm City Current
Stay connected