Forecasting Methods-The Difference & Why!

You might have noticed that as the lead forecaster for R.W.S and the creator of the maps that are made for specific individual events...that majority of the time only one map is made. While many of your forecasters will issue maps several times as updates for events...I choose to issue majority of times one single map. That map is usually issued within 24 hours of an event. You may ask yourself why I choose to do forecasting this way. 

Well, to answer that, when a map is issued within 24 hours of the event..based on the models and ensembles (whether they be GFS, NAM, ECM, SREF, or a combination) the forecasters skills should be able to anticipate slight changes and incorporate them into that original map. There are some exceptions to this forecasting method that would require another maps issuance. 

For example: In Winter

24 hours or less before an event a map is issued an ensembles and models are showing the heaviest snow zone over the I-95 corridor. Then within 12 hours of the event the models and ensembles now move that heaviest zone west by 100 miles. Then this would require the issuance of another map

In Summer

24 hours or less before an event a map is issued based on the models and ensembles showing the best Parameters over the I 95 corridor...but as time draws nearer the models and ensembles now show a shift to the north of 200 miles. Then another map would be issued..Also in summer time if when the map is issued for severe weather and parameters do not really meet a slight risk and a low risk is issued instead, the territory that is highlighted as low risk should be the only area that receives severe weather. In other words, even though a low risk is issued, instead of slight, severe storms are anticipated and expected to not occur outside that area. 

At times I debate whether its neccessary to even differentiate between   a low risk (5%) to a slight risk (15%) because technically either 5% or 15% is still a low risk leaving a 85%-95% chance of that severe weather not actually occurring. So after I discuss this with my partner..R.W.S when issuing a map just might highlight the regions that should expect severe weather instead of the risk percents.

These examples do happen and occur...so from time to time you might see an updated map issued.

Whenever a map is required to be issued for a 1 day event..it is an R.W.S policy that the map be issued 24 hours or less before the event and before SPC issues there 1 day event map (during the summer) 

So I hope that explains the reason that only one map is issued per event! Thank you for reading and if you like, please let me a comment to let me know what you think!