I provide a weather email service for people in MD. I am a storm chaser & Skywarn spotter. For daily weather tidbits follow me on Twitter: @wxmanMD.
By: cws6196, 5:34 PM GMT on December 28, 2008
After a look at the models and data I am sticking to my previous post forecasting a rain event this Friday. There was a previous hint of snow but I just don't see it. Early in the morning Friday there could be a light snow shower, but any precip after that should be rain as the temps will be in the mid 30s or even 40s.
Today (Wednesday) don't be surprised if a wind advisory is issued as we should experience winds in the 20 + mph for most of the day into the evening.
I hope everyone had a wonderful Christmas! Just a quick note to mention a future disturbance I am watching. Over the past few days the models have indicated (with inconsistency) a storm system for New Year's weekend. As this is a week away and the models have changed daily, I am not positive as to what will happen, but at this time my forecast is for rain if there is precip.
Updated: 5:06 AM GMT on December 31, 2008
By: cws6196, 1:55 PM GMT on December 24, 2008
May you and your loved ones have a very Blessed and Peace-filled Christmas!
By: cws6196, 5:06 PM GMT on December 21, 2008
Happy First Day of Winter!!!!
We missed the snow others are getting and I don't see us having a white Christmas - but we will see the white stuff eventually.
By: cws6196, 2:31 PM GMT on December 17, 2008
A look at the latest graphics and data lead me to stick with my previous forecast post from yesterday. This will mainly be a rain event, but in the evening, overnight and morning times surfaces could freeze and the precip could be freezing rain or snow. Any frozen precip will only slightly accumulate. Those along and North of the MD/PA line could see more accumulation.
Well, looks like I have to disagree with what the NWS put out yesterday. As I look at the models and other data I just don't see this as a major storm event that would lead us to needing tickets to Miami.
Here is how I see it: Saturday evening into the night the precip will start out as freezing rain, possibly turning to snow for a bit, then to rain then back to freezing rain again Sunday. The storm will start from the South and move North on Saturday, ending Sunday from the West to the East. So depending where you are located will determine the timing for you. The overnight and morning hours are when I am concerned regarding freezing rain and snow. During the day Sunday should be rain. The temps in the atmosphere are too warm to support all snow, but in the overnight hours the ground could be could enough to support freezing rain (precip falling as rain but freezing on contact).
I don't see much accumulation at this time.
Hmmm...... the local NWS is getting bold in their long range forecasts. Typically they are quite conservative. Here is the latest AFD: "KEEP YOUR EYE ON LATE SAT NGT INTO SUN. SIG WINTER EVENT MAY BE UNFOLDING DRG THIS TIME. GFS IS GETTING CONSISTENT IN SHOWING A VERY CLASSIC PTN FOR WINTER WX IN THE METRO AREAS AND POINTS W. IAD FCST MAX TEMP OF 33 IS DOWN A DEG VERSUS YESTERDAYS MEX MAX GUIDANCE FOR SUN AND IT WILL START OFF BELOW FRZG TO START THE EVENT. 850 MB TEMPS START THE DAY AT MINUS 7 IN THE MTNS WITH SFC SYSTEM FCST OVR KY AT 12Z SUNDAY. 2NDRY LOW THEN BEGINS TO FORM ALG THE CAROLINA COAST. AGAIN...STAY TUNED. IF YOU DON'T LIKE WINTER WX...MIGHT BE A GOOD TIME TO CALL YOUR FAVORITE AIRLINE AND GET THAT TICKET TO MIAMI."
I haven't yet looked at the models myself and in my next update will look at the moisture potential. They also mention a Low forming off the Carolina coast. Typically when that happens and there is cold and moist air in the area we get hit with large snow accumulations. The factors to look for is how cold and the position of the Low. That is what makes forecasting for this area tricky.
Well, just wanted you all to see what could be happening, and, as they suggest, if you wish to get airline tickets do so now. I will look at the model runs today to see if there is any consistency before I say too much more at this time. Just because one model on a run shows this does not mean it will continue to show this in later runs. I also want to see what the other models are saying.
Updated: 4:33 PM GMT on December 19, 2008
By: cws6196, 5:08 AM GMT on December 08, 2008
Friday Morning event
Ok, what happened here? Last evening's radar looked good, I was consistent in my forecast, the NWS finally agreed with me, but this morning, no white stuff!! Nothing on the current radar, and my local temp is above freezing. Did Mother Nature not receive my forecast last evening?! Or was it simply ignored ....
Well, I recorded 1.78 inches of rainfall from this event. There does not appear to be any threat of wintry precip the remainder of today and expect only scattered light rain the rest of the day. The weekend looks to be fine.
Thursday morning update
Still not an easy storm to forecast, but after looking at the data and reading other opinions from meteorologists, I actually want to stick with my forecast. Timing is everything and that is at issue. The rain will continue to build in from the South as the Low develops. As Thursday night rolls around the cold air from the Great Lakes will be moving in. Overnight Thursday can see a mix of precip from rain to sleet to snow. For most of us the precip should be done by Friday Noon. I will continue to say not more then 2 inches of snow, but realistically if we receive more then an inch I will be surprised (those North and West of Baltimore could see closer to two).
So bottom line I stand by what I have been saying. By the way, had the cold air moved in quicker and hit this system earlier Thursday (as originally seen in the models), we would have received about 10 - 20 inches of snow here ...
Wednesday morning update
The models are still not in much agreement regarding the weather Thursday into Friday. Here is the latest AFD: "DUE TO THIS COMPLEX SETUP...THERE IS NOT A HIGH CONFIDENCE IN THE PTYPE FORECAST...AND TOO LOW OF CONFIDENCE TO ISSUE A WINTER STORM WATCH ATTM. WILL LET THE EVENING SHIFT ANALYZE THE LATEST GUIDANCE BEFORE ISSUING ANY HEADLINES." At least through Wednesday I want to see what the data shows before making any changes to my previous forecast. So for now I am sticking to my forecast, allowing for timing differences.
Tuesday morning update
The forecast still is tricky for the end of the week as the models are all over the place. But let me summarize what I feel could happen. But first, my previous forecast for Tuesday stands with rain approaching Tuesday late afternoon through most of Wednesday. This should be all rain for those in Central Maryland. Thursday dries out and cools down (almost 30 degrees cooler then Wednesday).
The issue is the possible Low forming off the coast as the week progresses. Some models have it forming whole the euro model has it inland. I have seen model data giving us snow Thursday night through most of Friday, and others not starting the snow until later Friday. So we shall see.
What do I think? At this time I think we will have snow on Friday, when it starts I am not as yet sure. Accumulation; I don't see much more then 2 inches tops.
It looks like this week will be quite interesting and the models are not too sure how to handle it. So, I will do my best at the moment, but trust me, there will be changes as the week progresses. Right now I am confident that the Tuesday night into Wednesday event will be a rain event for us. But, the further into the evening the rain lasts the greater the chance for it to turn to snow. Those W of I-95 and toward the MD-PA line will have a better chance at snow, but again, just a dusting to an inch.
The confusing time comes Thursday into Friday. There appears the potential for a coastal Low, but what that means for us is not yet sure. I don't want to say too much at this time as I don't want to "panic" people ... but seriously, the models have not yet agreed on a solution, and saying much more would be merely a guess on my part.
Updated: 12:39 PM GMT on December 12, 2008
By: cws6196, 9:08 PM GMT on December 02, 2008
As stated below, the snow began to fall after 4:00pm, ending around 10:00 pm or so. I measured about 0.6".
The latest model data is moving up the systems I previously mentioned. It looks more likely we will see snow Saturday and now a possibility for a Tuesday storm as well.
Concerning Saturday, most of us will start to see precip after 4:00 pm. Given the temps this will be in the form of snow. But, there is not much moisture associated with this system, so a dusting to an inch is all we should have.
Tuesday has another system moving in, again, not much moisture, but this is tougher to call in regards to precip type. It does appear most of us will have periods of sleet while those closer the MD/PA line will see light snow. As this is a week out I don't yet want to speak of timing.
Hmmm..... back to looking at model data for next week. Here is the latest AFD from Sterling, VA: "HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC COAST SATURDAY AND THE NEXT COLD FRONT WILL PASS THROUGH THE REGION SATURDAY NIGHT INTO SUNDAY. THIS FRONT WILL ALSO HAVE LIMITED MOISTURE TO WORK WITH...BUT ANY PRECIPITATION THAT DOES FORM WOULD BE IN THE FORM OF SNOW SHOWERS. KEPT SLIGHT CHANCE/CHANCE POPS IN THE FORECAST FOR NOW WITH THE HIGHEST POPS ACROSS THE NORTHERN AND WESTERN CWA. ANY PRECIPITATION AMOUNTS WILL BE LIGHT. BLUSTERY CONDITIONS ARE EXPECTED BEHIND THE FRONT SUNDAY AS HIGH PRESSURE SLOWLY BUILDS TOWARDS THE REGION. THIS HIGH WILL BUILD OVER THE REGION SUNDAY NIGHT INTO EARLY NEXT WEEK. THE NEXT STORM SYSTEM MAY APPROACH TOWARDS THE MIDDLE OF NEXT WEEK."
Basically what they are saying is there is a slight chance for precip this weekend, and if that occurs it would be in the form of snow. But, we are only talking a dusting or so, if it happens at all. I will monitor that, but that is not what caught my attention. The last line is what interests me. At this time some data shows a growing Atlantic Low that could affect the area.
I don't like to mention this as early as this, but since the local NWS is talking about it I figured I would too. Confidence is not high on my part that this will happen, but know I will be monitoring it to see if this really does develop. Projected temps into December do show us below average, so snow is a possibility with any mention of precip.
Updated: 2:53 PM GMT on December 07, 2008