Prediction for Monday Snow/Ice

Now, everyone is aware of this threat and is making maps/predictions for this threats. Not all of the news channels maps are out, but they will be out soon. Anyways, there is an advisory for N&W MoCo, while there is a special weather statement for S&E MoCo. The advisory says 1-2 inches of snow, with a light glaze of ice(still enough to cause issues)! The timings say the system will start 1-4 AM, and the snow will change to a wintry mix of ice/sleet. It says by Monday afternoon, it should be all rain. The statement says that the snow/sleet is possible Monday morning, mainly after 4 AM. The accumulations say up to 1 inch, with no expectations of ice. It should be mostly rain by 11 AM-12 PM. This system is difficult to predict if there will delays or not, but NOAA has a map predicting if there will be delays or not. Now, lets look at it!

As you can see, MoCo(as a whole) is in the Probable zone, which means that there is a 70-85% chance of a delay, so for our county, they are leaning towards a delay. I can see why they would say that, since there's ice and snow happening in the rush hour, and it shouldn't be rain until 11AM-12PM. Lets look at where NBC 4 thinks the impacts will be!

About 60% of MoCo is in the "Biggest Impacts" area, while the other 40% is in the minor impacts. Northern Rockville and any place north than that will have the biggest impacts. This means that delay are likely and closures are possible. Since the majority of MoCo will have the biggest impacts(and since MCPS makes a decision for the whole county), they might have to delay. We are going to look at WUSA 9's snowfall map.

As you can see from WUSA 9's map, about 86% of MoCo is in the Trace-1" area, while Damascus and Barnesville is in the 1-2" area. And here is the bad part: After you go south of MoCo, there is no snow accumulation expected. That means that we are the edge of snow accumulations. This will not give us much impacts, but we still have the freezing rain that may convince MCPS for a delay. Howard Bernstein himself said in a tweet that this advisory/system will be more on the ice and sleet. Now lets look at the ice accumulation map by NWS.

According to this, about 50.01% of the county will see some ice accumlation. It is not expected to be over a tenth of ice, but a few hundredths of ice. This is still enough to cause delays and impacts. Like I said before in my earlier posts, even a small amount of ice is enough to cause widespread delays/closures and impacts. Now let's look at the NWS snowfall map! UPDATE: REPORTING 2 INCHES OF SNOW IN GAITHERSBURG.

The NWS upped their snowfall totals, with about 45% of the county in the 1-2" area now. The other 55% is in the <1" area, but since they are close to the 1-2 inches area, the other 55% of MoCo should be in the 0.5-1" areas. Now lets look at what ABC 7 thinks will happen in our area!

ABC 7 says light snow to ice to regular rain for the whole county, while Damascus is in the snow to ice area(accumulations likely!). This map says that delays are likely. Now, with all this info, it is time to make my snowflake prediction!

Snowflake Prediction: 3 snowflakes(find ratings at the ratings page)

Unlike the last time we had a system like this(last Tuesday), this is way bigger of a threat. Ice, with snow, and with the mix changing to rain around 11AM-12PM, has a much higher chance of a delay and closure becomes a possibility. In our N and W suburbs, it will be a mess. Temperatures will be below or at the freezing mark tonight, so snow and ice will stick to sidewalks, and even roads(most likely salted though). It has been a lot colder lately, and it wasn't that warm today (<50 degrees). It will be snowing at when students leave for school, with snow sticking in most places with the temps below or at freezing, so a delay will most likely be needed. About the closure chance. Yes, I do think there is a chance of closure, but this is because the cold air(wintry mix) will stay long enough in some places that when the high schoolers/middle schoolers go to school at a delayed opening, there will still be ice/snow. The closure will happen IF the cold air stays long enough(until 11:45AM-12:00PM or longer) for the snow/ice to accumulate. They will send students on a delay if the rain starts at 10-11AM. If the amounts are to the higher end, I would say a closure(3.5 snowflakes), but not much people are saying/suggesting a closure and there will have to be ice accumulations for at least 75% of the county. If the whole county has an inch or more with ice accumulations that make slick spots, there will be a closure. S&E MoCo is in a Special Weather Statement, which implies that there might be impacts, but they will be very insignificant. An advisory means that there will be impacts, and they might be somewhat significant. A closure could happen even with the same amounts, but the accumulations have to stay for long. They make a decision for the whole county, so they might "ignore" that and close. There will have to be a little bit more ice/snow/sleet for a closure(like 0.1 inches more for snow/sleet)(0.01-0.03" more ice), and they have to last long(10:50AM and longer).(UPDATE: NO SCHOOL FOR MCPS 12/16/2019).

Monday Snow/Ice Threat Update

Not much people are really aware of this threat, except for a few people, which is kinda weird, considering the system is TOMORROW. Anyways, there is no maps from the news channels/Capital Weather Gang, but I assume by tonight more people will be watching the threat and making maps. Right now, we only have raw model data and the NWS map. Anyways, it looks like an inch is the most amount of snow most of the county will get, but I think that there is the chance of 2 inches of snow. But, the threat will also include... FREEZING RAIN! What is the good thing about that? Any amount of freezing rain (even 0.01 inches!) will cause issues. Why? Because its pure ice, and ice is very slippery. Combined with the accumulated snow, that will cause lots of issues, one of them being the snow being harder to remove. It will change into all rain though. The timing of this storm(for the whole county)(wintry weather) is 11PM Sunday to 9AM Monday(GFS shows until 12PM Monday)(there is a chance of a wintry mix/snow at 10 PM Sunday). After 9 AM, the whole county is switched to rain(the majority of the models say so), but the rain will eventually melt the snow(not all of it), but it also may actually make the conditions worse. In our N and W areas, the rain might make the snow into slush, which will make it unsafe for longer. I am sure plows and salt trucks will try their best to prevent this, but on neighborhoods, plows won't get to the neighborhoods quick enough to prevent this(they will prevent this on main and most likely secondary roads). Anyways,  I will show you some data now(snow depth)(when the accumulations are at its most).

Euro(10AM): 1.2- 2.8 inches(most of the county on 1.6-2 inches, 1 area in 2-2.8 inches, and Damascus is in 1.2-1.6 inches)(the east loses, even if you are north of MoCo and even Maryland).

GFS(10AM): 0.4 inches-2 inches(most of county in 0.8-1.2 inch area)(extreme southern MoCo in 0.4-0.8 inches area)(N and W MoCo in 1.2-1.6 inches area)(Barnesville in 1.6-2 inches area)(the more north you go the more snow you get)(this model shows a lot of freezing rain/ice in the area)(I couldn't find ice accumulations).

CONUS HD(7AM): 0.04-0.8 inches(Western-Southern MoCo in 0.04-0.2 inches)(rest of county in 0.2-0.4 inches)(Poolesville, Clarksburg, and Barnesville get 0.4-0.8 inches of snow).

According to these models, the highest accumulation time is around 7-10 AM, which means that the timing is perfect for a delay since students leave around 6-9 AM for school. 1 or more inches of snow combined with ice is an unsafe commute for school, so MCPS might have to put a delay for the crews and the rain to melt the ice/snow(closure isn't an option since by 11AM-12PM snow/ice will be off the ground and it will be pure rain)(the cold air has to last until 12 PM for a closure in my opinion). Now, let's look at the NWS maps!

As you can see, most of the county(3/4) is in the less than an inch area, while the other 1/4 is in the 1-2 inches area. This is a map that I agree with, but I would move the 1-2 a little bit more south. Now, let's look at what the NWS has to say about the amounts for MoCo(exact)!

As you can see, 5 places in the county will see less than an inch(Burtonsville, Chevy Chase, Rockville, Silver Spring, Takoma Park), while Damascus, Germantown, and Poolesville will see about an inch. There is an above 50% chance for the whole county to see at least a coating(0.1 inches). There is a 1-65% chance that the whole county will see above an inch of snow(only Damascus and Poolesville have an above 50% chance that they will see over an inch)! Now, let's look at the NWS ice accumulation map!

As you can see, about 55% of the county is in the 0.01-0.10 inches of ice area. Even though this is very little, any amount of ice is enough to cause issues. Now that we looked at all the data that we can get,I can conclude that this is all we need to cause a delay, snow, sleet, and ice! My snowflake prediction should come out by 7:45PM EST.

Freezing Rain Friday

There is a winter weather advisory just north and west of MoCo(as a whole). There is a special weather statement for the whole county though. It says that there is a 30-50% chance that there will be freezing rain tomorrow, but the NWS map shows almost no ice accumulation(at all) in the county except for 1 small area. The only places who have any chance of getting freezing rain(in my opinion) is people who are in Gaithersburg to the Damascus area(basically the northern half of MoCo)(maybe Northern Rockville).  And even if there is freezing rain, it probably won't last long enough to cause issues at all or not accumulate at all.

If this was snow, I would give this 1 snowflake, but since even a small amount of freezing rain can cause lots of issues, I will give this 1.5 snowflakes(35% chance of delay). We will get a delay if we get lucky and the cold air lasts long enough for the ice to stay for a while.

Monday Snow Threat?

Yes, the winter season has officially started. I am now getting lots of snow/wintry mix threats, and it just so happens that the Euro model(the historically most correct model) is showing a snow turning into a mix turning into rain on Tuesday. If this were to happen, the most likely delay(not 2 hr delay) would be an early release(if we do get an impact on our school day), since the snow starts around 12:00 PM and turns into mix around 9-10:30 PM Monday, then turns into all rain(ice for Damascus!) at 10:30PM(Monday)-12:00 Tuesday. This tweet from Howard Bernstein shows the threat better than I do.

I don't think you can see, but the snow(light) starts at 12 PM Monday, snowing moderately hard at 4 PM, and at 8 PM, you can see the mix coming, but it doesn't touch MoCo. Still snowing hard at 8 though. You can see that the rain is starting to push through, and the rain represents the warmer air. I will keep you updated on this threat, but remember, threats like this are known to disappear quickly.

Final Prediction for Wednesday Snow

This system is already happening as I write. It is raining and temperatures are starting to drop. It went from 56 to 52 at 3:45 PM, in Gaithersburg. I looked at the radar a couple minutes ago, and it already shows snow/ice moving into the DMV(mostly in the mountains). We are not expecting any ice though, only snow, sleet and rain. Anyways, there is a winter weather advisory(first!) for North and West MoCo and a Special Weather Statement for Southern and Eastern MoCo. The advisory expects 1-2 inches for North and Western MoCo and the statement expects less than an inch for Southern and East MoCo. For the whole county, the winter forecast is Trace-2 inches, and the snow/mix is expected to come between 12AM to 4AM Wednesday. If you live north and west of MoCo, such as in Urbana, you will see more snow. Even though I say the more north/west the more snow, this is one of those situations where if you go too north(border of Pennsylvania and Maryland), you might not get as much snow as a place such as Damascus. Since the threat is just a day away, we won't be looking at models anymore and news channel forecasts instead. Lets look at the NWS map now.

REPORT: 8:20 PM: I got a report that snow was falling in Damascus. This is much, much earlier than expected. The cold air will push down to Germantown, then Gaithersburg, then Rockville, then Bethesda.

As you can see, the map shows less than an inch for 67% of MoCo and 1-2 inches for Northern
MoCo. There is not much more to say about this. Let's move on to WUSA 9's map.

The map shows Trace-1 for 55% of MoCo while the other 45% is in the Trace-2 area. This doesn't actually mean that the northern side of MoCo will get over an inch, it is just saying that there is more potential for higher snow amounts in the area. That area can still get a trace of snow. Now, lets look at the FOX 5 map.

FOX 5 shows all of the county in the "Coating to 2" Of Slush/Snow area. This is saying that slush/snow won't only accumulate in the grass, it is showing that there MAY be slush/snow on the sidewalks and secondary roads. This is the kind of situation that would give us a 2 hour delay. Again, it doesn't say that there will be over an inch, it is saying that there could be 2 inches. In this system, the slush will make more of an impact than snow. Now, lets look at NBC 4's map.

NBC 4 has 2/3 of MoCo in the 1-2 inches area, while the other 1/3 is in the Coating-1 inch area. This is showing that 2/3 of MoCo WILL get at least an inch, but no more than 2 inches. The other 1/3 of MoCo will probably get near an inch, since they are close to the 1-2 inches area(0.60 inches and higher). The other 1/3 of MoCo can still get less than 0.5 inches(or a coating). Now, I am going to show you ABC 7's map.

This map... is actually kind of difficult to interpret. Why? This is because the different colors blend in with the other colors. Anyways, according to my interpretation, 75% of MoCo is in the 1" is the most area and the other 25% is in the 1-2 inches area(anything that is darker blue than the light blue is 1-2 inches area). Finally, lets look at the Capital Weather Gang's map(note that this may not be the latest map because this is the latest map I can get without subscribing to them).

This map shows 2/3 of MoCo in the Trace to 1" area, while the other 2/3 is in the Coating to 2" area. For the 2/3 of the county that is in the T-1" area, it says most accumulation on grassy areas, but some accumulations can be on the sidewalks. This area's boom(higher than expected outcome) is 1-2 inches, and the bust(lower than the expected outcome) is no snow at all. The other 1/3 of the county is in the Coating to 2" area. This is the area where the most accumulation is expected. The boom for this area is 2-4" and the bust is bare ground(snow but no accumulation, even grass). Finally, lets move on to my FINAL prediction.

Prediction for Wednesday 12/11/2019: 2 snowflakes

This is one of the first times that I am 50/50 between a decision.  I am not leaning to a full day or a delay, I am 50% percent sure of a delay and 50% sure of a full day. I can't decide. Like I said in an earlier post, snow in the early morning that ends around 7-8 AM can really cause some issues. It wouldn't be a good idea to send students walking in the snow/slush, but at the same time, the accumulations and surface temperatures may not be enough to even cause much of an issue. There will be more slush than snow, so the slush will be an issue. MCPS has not done any delay/closure/early dismissal due to inclement weather conditions, so they might be a little easier on the decision to delay or not(needs a lot more snow to close). A delay would really help, because it would give time for the temps to rise and for crews to treat the snow. It will be really cold, so some water could freeze and there could be slick spots(likely in Northern and Western MoCo). Roads will be fine, but sidewalks and neighborhoods may have slush(secondary roads could have slush(45% chance). It all just depends how much snow falls. Over .80 inches will cause slush issues. There is an advisory for North and West MoCo, which will impact MCPS's decision. It all depends how cold it is and how much snow it falls. There might be a delay, so prepare for a full day because there is a 50% chance(it could happen it could not happen).

UPDATE: REPORTING ONLY A COATING(1/2 a centimeter of snow) in Gaithersburg. How much snow did you get? School opening on time.Storm wasn't a bust but snow was to the lower end.

Update on Wednesday Snow

This threat is still a threat, which is good, considering threats like this quickly disappear. Anyways, the models are suggesting snow, but the amount of snow is different for each model. They are around the amounts of 1-3 inches, which could cause lots of delays. The Euro shows 1.6 to 2.8 inches(2-2.8 inches for most of county), and the GFS shows 1.6 inches(most of county)-2.8 inches(small area)(snow depths at 6 AM). But remember, highs will be in the 60's on Tuesday, so the amount of snow that accumulates will not be as much as the amount of snow that falls. Now, let me show you when the rain changes into snow.(Picture: WUSA9).

As you can see, all of MoCo is expected to switch to snow at Wednesday, in the time range of 1 AM to 4 AM, but for MoCo I would say 1 AM-2:45 AM. This is how fast the cold air will reach us while the moisture is still there, so the earlier the better. FOX 5 has released their first call for this system.

As you can see, 3/8 of MoCo is in the "Mix Favored(Slushy/Grassy Coating) and the other 5/8 is in the "Spotty Coating to 2" area. This actually favors us because slush is actually very slippery and can become dangerous to MCPS students who are going to school.  These are some of the highlights of the system that is coming through.

ABC 7 says that rain will change to sleet to snow between 12 AM-3AM Wednesday. Accumulations will be mostly on cars, trees, grass, etc. And this is the most exciting part, PLAN FOR POSSIBLE SCHOOL DELAYS. Now finally, lets look at the NWS map.

As you can see, about 98% of MoCo is in the 1-2 inches area. So according to this, MoCo will get 0.9-2 inches of snow. This will cause some issues, and definitely a lot of slush. Out of this info I will make my first snowflake prediction of the 2019-2020 winter!

Snowflake Prediction: 2 snowflakes(no picture because not final prediction)

1-2 inches in the morning and ending at noon can really cause some issues. I would be more confident in a delay if temperatures in Tuesday weren't so hot, but the rain will help. Some of the rain will be able to freeze on Wednesday, and that can cause slick spots. There won't be much accumulation on the sidewalks and roads, but there will be slush, which is still bad. Sending kids to school while it is snowing and when there is slush and some slick spots will be bad, so a delay will help a lot of crews to treat the snow. MCPS is also more likely to delay because we haven't closed at all this year, so MCPS might be nice and give us a delay/(unlikely)closure.(don't get your hopes up though!) This isn't a final prediction, it might change tomorrow.

Snow on Wednesday?

I have been looking a little bit for some snow threats, and I have finally found one. On Tuesday, there's a storm system that starts as rain, then mixes as rain/snow, then becomes fully snow. But, the temperatures on Tuesday and Monday are in the upper 50's and lower 60's. That might reduce the stickage of snow, but the good thing is that the temperatures will drop drastically during the night of Tuesday, when it rains. Although this will change, I will give the snow amounts the models are giving(how much snow has fallen/accumulated at 6 AM)(as of 4:00 PM)

Euro(European Model): 1.6 inches- 4 inches(most optimistic for this system)(has more areas than the GEM in the 2.8 inches to 4 inches area)(about 40% of MoCo is in 2.8 inches to 4 inches area)(57% percent in the 2-2.8 inches area)(3% of MoCo in 1.6-2 inches area)

ICON(German Model): Trace(0.04 inches)- 0.4 inches(least optimistic for this system)(according to this only the most southern quarter will get snow falling/accumulations)

GEM(Canadian Model): 1.6 inches-4 inches(only one certain region of MoCo is in the 2.8-4 inches area)(almost rest of MoCo is in 2-2.8 inches area)(and only one very small upper western region has 1.6-2 inches snowfall)

GFS(American Model): 0.2 inches-1.6 inches(1% of MoCo is in the 0.2-0.4 inches area)(southern MoCo is in the 0.4-0.8 inches)(rest of MoCo is in the 0.8-1.2 inches region)(Damascus is in the 1.2 inches to 1.6 inches area)


Where I got this info: https://weather.us/

P.S: I am sorry the winter forecasts aren't out yet, they should be out by this week.